CVE-2025-21731

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-21731", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.755Z", "datePublished": "2025-02-27T02:07:35.927Z", "dateUpdated": "2026-11-10T12:34:49.767Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:05:20.600Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: don't allow reconnect after disconnect\n\nFollowing process can cause nbd_config UAF:\n\n1) grab nbd_config temporarily;\n\n2) nbd_genl_disconnect() flush all recv_work() and release the\ninitial reference:\n\n nbd_genl_disconnect\n nbd_disconnect_and_put\n nbd_disconnect\n flush_workqueue(nbd->recv_workq)\n if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...))\n nbd_config_put\n -> due to step 1), reference is still not zero\n\n3) nbd_genl_reconfigure() queue recv_work() again;\n\n nbd_genl_reconfigure\n config = nbd_get_config_unlocked(nbd)\n if (!config)\n -> succeed\n if (!test_bit(NBD_RT_BOUND, ...))\n -> succeed\n nbd_reconnect_socket\n queue_work(nbd->recv_workq, &args->work)\n\n4) step 1) release the reference;\n\n5) Finially, recv_work() will trigger UAF:\n\n recv_work\n nbd_config_put(nbd)\n -> nbd_config is freed\n atomic_dec(&config->recv_threads)\n -> UAF\n\nFix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so\nthat nbd_genl_reconfigure() will fail."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/block/nbd.c"], "versions": [{"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e70a578487a47d7cf058904141e586684d1c3381", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "6bef6222a3f6c7adb6396f77f25a3579d821b09a", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e3be8862d73cac833e0fb7602636c19c6cb94b11", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e7343fa33751cb07c1c56b666bf37cfca357130e", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "d208d2c52b652913b5eefc8ca434b0d6b757f68f", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302", "status": "affected", "versionType": "git"}, {"version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "844b8cdc681612ff24df62cdefddeab5772fadf1", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/block/nbd.c"], "versions": [{"version": "4.12", "status": "affected"}, {"version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.291", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.76", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.13", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.13.2", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.4.291"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.10.235"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.15.179"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.1.129"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.76"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.13.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.14"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381"}, {"url": "https://git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a"}, {"url": "https://git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11"}, {"url": "https://git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e"}, {"url": "https://git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f"}, {"url": "https://git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739"}, {"url": "https://git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302"}, {"url": "https://git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1"}], "title": "nbd: don't allow reconnect after disconnect", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2025-21731", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-02-27T17:58:00.860096Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T18:02:27.838Z"}}, {"title": "CVE Program Container", "references": [{"url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:36:36.130Z"}}, {"x_adpType": "supplier", "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-11-10T12:34:49.767Z"}, "affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:36:36.130Z"}}, {"affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "x_adpType": "supplier", "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}], "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-11-10T12:34:49.767Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2025-21731", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-02-27T17:58:00.860096Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T17:58:02.900Z"}}], "cna": {"title": "nbd: don't allow reconnect after disconnect", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e70a578487a47d7cf058904141e586684d1c3381", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "6bef6222a3f6c7adb6396f77f25a3579d821b09a", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e3be8862d73cac833e0fb7602636c19c6cb94b11", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "e7343fa33751cb07c1c56b666bf37cfca357130e", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "d208d2c52b652913b5eefc8ca434b0d6b757f68f", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302", "versionType": "git"}, {"status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "lessThan": "844b8cdc681612ff24df62cdefddeab5772fadf1", "versionType": "git"}], "programFiles": ["drivers/block/nbd.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"status": "unaffected", "version": "0", "lessThan": "4.12", "versionType": "semver"}, {"status": "unaffected", "version": "5.4.291", "versionType": "semver", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.235", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.179", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.129", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.76", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.13", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.13.2", "versionType": "semver", "lessThanOrEqual": "6.13.*"}, {"status": "unaffected", "version": "6.14", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/block/nbd.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381"}, {"url": "https://git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a"}, {"url": "https://git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11"}, {"url": "https://git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e"}, {"url": "https://git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f"}, {"url": "https://git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739"}, {"url": "https://git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302"}, {"url": "https://git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: don't allow reconnect after disconnect\n\nFollowing process can cause nbd_config UAF:\n\n1) grab nbd_config temporarily;\n\n2) nbd_genl_disconnect() flush all recv_work() and release the\ninitial reference:\n\n nbd_genl_disconnect\n nbd_disconnect_and_put\n nbd_disconnect\n flush_workqueue(nbd->recv_workq)\n if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...))\n nbd_config_put\n -> due to step 1), reference is still not zero\n\n3) nbd_genl_reconfigure() queue recv_work() again;\n\n nbd_genl_reconfigure\n config = nbd_get_config_unlocked(nbd)\n if (!config)\n -> succeed\n if (!test_bit(NBD_RT_BOUND, ...))\n -> succeed\n nbd_reconnect_socket\n queue_work(nbd->recv_workq, &args->work)\n\n4) step 1) release the reference;\n\n5) Finially, recv_work() will trigger UAF:\n\n recv_work\n nbd_config_put(nbd)\n -> nbd_config is freed\n atomic_dec(&config->recv_threads)\n -> UAF\n\nFix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so\nthat nbd_genl_reconfigure() will fail."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.4.291", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.235", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.179", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.129", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.76", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.13", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.13.2", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.14", "versionStartIncluding": "4.12"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:05:20.600Z"}}}, "cveMetadata": {"cveId": "CVE-2025-21731", "state": "PUBLISHED", "dateUpdated": "2026-11-10T12:34:49.767Z", "dateReserved": "2024-12-29T08:45:45.755Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2025-02-27T02:07:35.927Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/block/nbd.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "e70a578487a47d7cf058904141e586684d1c3381", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "6bef6222a3f6c7adb6396f77f25a3579d821b09a", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "e3be8862d73cac833e0fb7602636c19c6cb94b11", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "e7343fa33751cb07c1c56b666bf37cfca357130e", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "d208d2c52b652913b5eefc8ca434b0d6b757f68f", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}, {"lessThan": "844b8cdc681612ff24df62cdefddeab5772fadf1", "status": "affected", "version": "b7aa3d39385dc2d95899f9e379623fef446a2acd", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/block/nbd.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"lessThan": "4.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.4.*", "status": "unaffected", "version": "5.4.291", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.235", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.179", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.129", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.76", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.13", "versionType": "semver"}, {"lessThanOrEqual": "6.13.*", "status": "unaffected", "version": "6.13.2", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.14", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"affectedData": [{"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "0", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}], "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "7B038092-73B0-4839-99CE-440987948ED1", "versionEndExcluding": "5.4.291", "versionStartIncluding": "4.12", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "545121FA-DE31-4154-9446-C2000FB4104D", "versionEndExcluding": "5.10.235", "versionStartIncluding": "5.5", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "C708062C-4E1B-465F-AE6D-C09C46400875", "versionEndExcluding": "5.15.179", "versionStartIncluding": "5.11", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "2DA5009C-C9B9-4A1D-9B96-78427E8F232C", "versionEndExcluding": "6.1.129", "versionStartIncluding": "5.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A6D70701-9CB6-4222-A957-00A419878993", "versionEndExcluding": "6.6.76", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "2897389C-A8C3-4D69-90F2-E701B3D66373", "versionEndExcluding": "6.12.13", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6D4116B1-1BFD-4F23-BA84-169CC05FC5A3", "versionEndExcluding": "6.13.2", "versionStartIncluding": "6.13", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: don't allow reconnect after disconnect\n\nFollowing process can cause nbd_config UAF:\n\n1) grab nbd_config temporarily;\n\n2) nbd_genl_disconnect() flush all recv_work() and release the\ninitial reference:\n\n nbd_genl_disconnect\n nbd_disconnect_and_put\n nbd_disconnect\n flush_workqueue(nbd->recv_workq)\n if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...))\n nbd_config_put\n -> due to step 1), reference is still not zero\n\n3) nbd_genl_reconfigure() queue recv_work() again;\n\n nbd_genl_reconfigure\n config = nbd_get_config_unlocked(nbd)\n if (!config)\n -> succeed\n if (!test_bit(NBD_RT_BOUND, ...))\n -> succeed\n nbd_reconnect_socket\n queue_work(nbd->recv_workq, &args->work)\n\n4) step 1) release the reference;\n\n5) Finially, recv_work() will trigger UAF:\n\n recv_work\n nbd_config_put(nbd)\n -> nbd_config is freed\n atomic_dec(&config->recv_threads)\n -> UAF\n\nFix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so\nthat nbd_genl_reconfigure() will fail."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nbd: no permitir la reconexi\u00f3n despu\u00e9s de la desconexi\u00f3n El siguiente proceso puede causar el nbd_config UAF: 1) grab nbd_config temporarily; 2) nbd_genl_disconnect() flush all recv_work() and release the initial reference: nbd_genl_disconnect nbd_disconnect_and_put nbd_disconnect flush_workqueue(nbd->recv_workq) if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...)) nbd_config_put -> due to step 1), reference is still not zero 3) nbd_genl_reconfigure() queue recv_work() again; nbd_genl_reconfigure config = nbd_get_config_unlocked(nbd) if (!config) -> succeed if (!test_bit(NBD_RT_BOUND, ...)) -> succeed nbd_reconnect_socket queue_work(nbd->recv_workq, &args->work) 4) step 1) release the reference; 5) Finially, recv_work() will trigger UAF: recv_work nbd_config_put(nbd) -> nbd_config is freed atomic_dec(&config->recv_threads) -> UAF Fix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so that nbd_genl_reconfigure() will fail. "}], "id": "CVE-2025-21731", "lastModified": "2026-11-10T13:17:34.093", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-21731", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2025-02-27T17:58:00.860096Z", "version": "2.0.3"}}]}, "published": "2025-02-27T02:15:16.833", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: nbd: don't allow reconnect after disconnect", "id": "2348517", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2348517"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnbd: don't allow reconnect after disconnect\nFollowing process can cause nbd_config UAF:\n1) grab nbd_config temporarily;\n2) nbd_genl_disconnect() flush all recv_work() and release the\ninitial reference:\nnbd_genl_disconnect\nnbd_disconnect_and_put\nnbd_disconnect\nflush_workqueue(nbd->recv_workq)\nif (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...))\nnbd_config_put\n-> due to step 1), reference is still not zero\n3) nbd_genl_reconfigure() queue recv_work() again;\nnbd_genl_reconfigure\nconfig = nbd_get_config_unlocked(nbd)\nif (!config)\n-> succeed\nif (!test_bit(NBD_RT_BOUND, ...))\n-> succeed\nnbd_reconnect_socket\nqueue_work(nbd->recv_workq, &args->work)\n4) step 1) release the reference;\n5) Finially, recv_work() will trigger UAF:\nrecv_work\nnbd_config_put(nbd)\n-> nbd_config is freed\natomic_dec(&config->recv_threads)\n-> UAF\nFix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so\nthat nbd_genl_reconfigure() will fail.", "A vulnerability was found in the Linux kernel's Network Block Device (NBD) subsystem, specifically involving a use-after-free (UAF) condition in the nbd_config structure. The root cause is the improper handling of the NBD_RT_BOUND flag during the disconnect process. The fix involves clearing the NBD_RT_BOUND flag in nbd_genl_disconnect() to prevent reconfiguration after disconnection."], "name": "CVE-2025-21731", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-02-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-21731\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-21731\nhttps://lore.kernel.org/linux-cve-announce/2025022649-CVE-2025-21731-c18b@gregkh/T"], "threat_severity": "Moderate"}

{}