CVE-2021-47593

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Pero en caso de respaldo, aceptar() puede devolver un sk tcp simple. En tal caso, sk todav\u00eda est\u00e1 etiquetado como 'kernel' y setsockopt funcionar\u00e1. Esto bloquear\u00e1 el kernel. La extensi\u00f3n de subflujo tiene un socket NULL ctx->conn mptcp: ERROR: KASAN: null-ptr-deref en subflow_data_ready+0x181/0x2b0 Seguimiento de llamadas: tcp_data_ready+0xf8/0x370 [..]"}], "id": "CVE-2021-47593", "lastModified": "2026-06-17T04:17:50.150", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47593", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-09-10T17:12:30.519015Z", "version": "2.0.3"}}]}, "published": "2024-06-19T15:15:53.890", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: mptcp: clear 'kern' flag from fallback sockets", "id": "2293234", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2293234"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nmptcp: clear 'kern' flag from fallback sockets\nThe mptcp ULP extension relies on sk->sk_sock_kern being set correctly:\nIt prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, \"mptcp\", 6); from\nworking for plain tcp sockets (any userspace-exposed socket).\nBut in case of fallback, accept() can return a plain tcp sk.\nIn such case, sk is still tagged as 'kernel' and setsockopt will work.\nThis will crash the kernel, The subflow extension has a NULL ctx->conn\nmptcp socket:\nBUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0\nCall Trace:\ntcp_data_ready+0xf8/0x370\n[..]"], "name": "CVE-2021-47593", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-06-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47593\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47593\nhttps://lore.kernel.org/linux-cve-announce/2024061919-CVE-2021-47593-a7a7@gregkh/T"], "threat_severity": "Low"}

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