CVE-2020-28974

{"containers": {"cna": {"affected": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "descriptions": [{"lang": "en", "value": "A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. 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This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "n/a"}]}]}, "references": {"reference_data": [{"name": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804", "refsource": "MISC", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804"}, {"name": "https://seclists.org/oss-sec/2020/q4/104", "refsource": "MISC", "url": "https://seclists.org/oss-sec/2020/q4/104"}, {"name": "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7", "refsource": "MISC", "url": "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7"}, {"name": "[oss-security] 20201124 Re: Linux kernel slab-out-of-bounds Read in fbcon", "refsource": "MLIST", "url": "http://www.openwall.com/lists/oss-security/2020/11/25/1"}, {"name": "[debian-lts-announce] 20201210 [SECURITY] [DLA 2483-1] linux-4.19 security update", "refsource": "MLIST", "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html"}, {"name": "[debian-lts-announce] 20201218 [SECURITY] [DLA 2494-1] linux security update", "refsource": "MLIST", "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html"}, {"name": "https://security.netapp.com/advisory/ntap-20210108-0003/", "refsource": "CONFIRM", "url": "https://security.netapp.com/advisory/ntap-20210108-0003/"}]}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T16:48:01.280Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://seclists.org/oss-sec/2020/q4/104"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7"}, {"name": "[oss-security] 20201124 Re: Linux kernel slab-out-of-bounds Read in fbcon", "tags": ["mailing-list", "x_refsource_MLIST", "x_transferred"], "url": "http://www.openwall.com/lists/oss-security/2020/11/25/1"}, {"name": "[debian-lts-announce] 20201210 [SECURITY] [DLA 2483-1] linux-4.19 security update", "tags": ["mailing-list", "x_refsource_MLIST", "x_transferred"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html"}, {"name": "[debian-lts-announce] 20201218 [SECURITY] [DLA 2494-1] linux security update", "tags": ["mailing-list", "x_refsource_MLIST", "x_transferred"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html"}, {"tags": ["x_refsource_CONFIRM", "x_transferred"], "url": "https://security.netapp.com/advisory/ntap-20210108-0003/"}]}]}, "cveMetadata": {"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "cveId": "CVE-2020-28974", "datePublished": "2020-11-20T17:49:57.000Z", "dateReserved": "2020-11-20T00:00:00.000Z", "dateUpdated": "2024-08-04T16:48:01.280Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

{}

{"affected": [{"affectedData": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "source": "cve@mitre.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0AA34C8B-74C6-4577-B819-F87CB15BA101", "versionEndExcluding": "5.9.7", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*", "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height."}, {"lang": "es", "value": "Una lectura fuera de l\u00edmites en fbcon en el kernel de Linux versiones anteriores a 5.9.7, podr\u00eda ser usada por parte de atacantes locales para leer informaci\u00f3n privilegiada o potencialmente bloquear el kernel, tambi\u00e9n se conoce como CID-3c4e0dff2095. Esto ocurre porque la funci\u00f3n KD_FONT_OP_COPY en el archivo drivers/tty/vt/vt.c puede ser usada para manipulaciones tales como la altura de la fuente"}], "id": "CVE-2020-28974", "lastModified": "2026-06-17T03:10:56.083", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "LOCAL", "authentication": "NONE", "availabilityImpact": "COMPLETE", "baseScore": 6.1, "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "vectorString": "AV:L/AC:L/Au:N/C:P/I:P/A:C", "version": "2.0"}, "exploitabilityScore": 3.9, "impactScore": 8.5, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "PHYSICAL", "availabilityImpact": "HIGH", "baseScore": 5.0, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:H", "version": "3.1"}, "exploitabilityScore": 0.3, "impactScore": 4.7, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2020-11-20T18:15:12.120", "references": [{"source": "cve@mitre.org", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://www.openwall.com/lists/oss-security/2020/11/25/1"}, {"source": "cve@mitre.org", "tags": ["Release Notes", "Vendor Advisory"], "url": "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7"}, {"source": "cve@mitre.org", "tags": ["Patch", "Vendor Advisory"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html"}, {"source": "cve@mitre.org", "tags": ["Exploit", "Mailing List", "Third Party Advisory"], "url": "https://seclists.org/oss-sec/2020/q4/104"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://security.netapp.com/advisory/ntap-20210108-0003/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://www.openwall.com/lists/oss-security/2020/11/25/1"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Release Notes", "Vendor Advisory"], "url": "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Vendor Advisory"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Exploit", "Mailing List", "Third Party Advisory"], "url": "https://seclists.org/oss-sec/2020/q4/104"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://security.netapp.com/advisory/ntap-20210108-0003/"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"acknowledgement": "Red Hat would like to thank Yuan Ming <yuanmingbuaa@gmail com> (Tsinghua University) for reporting this issue.", "affected_release": [{"advisory": "RHSA-2021:1739", "cpe": "cpe:/a:redhat:enterprise_linux:8::nfv", "package": "kernel-rt-0:4.18.0-305.rt7.72.el8", "product_name": "Red Hat Enterprise Linux 8", "release_date": "2021-05-18T00:00:00Z"}, {"advisory": "RHSA-2021:1578", "cpe": "cpe:/o:redhat:enterprise_linux:8", "package": "kernel-0:4.18.0-305.el8", "product_name": "Red Hat Enterprise Linux 8", "release_date": "2021-05-18T00:00:00Z"}], "bugzilla": {"description": "kernel: slab-out-of-bounds read in fbcon", "id": "1903126", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1903126"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.0", "cvss3_scoring_vector": "CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:H", "status": "verified"}, "cwe": "CWE-125", "details": ["A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.", "An out-of-bounds (OOB) SLAB memory access flaw was found in the Linux kernel's fbcon driver module. A bounds check failure allows a local attacker with special user privileges to gain access to out-of-bounds memory, leading to a system crash or leaking of internal kernel information. The highest threat from this vulnerability is to system availability."], "mitigation": {"lang": "en:us", "value": "Add 'nomodeset' option as kernel boot parameter to disable frame buffering in /etc/default/grub, and run 'grub2-mkconfig -o /boot/grub2/grub.cfg' and reboot.\n~~~\n# cat /proc/cmdline \nBOOT_IMAGE=(hd0,msdos1)/vmlinuz-4.18.0-147.el8.x86_64 root=/dev/mapper/rhel_rhel8u2--1-root ro crashkernel=auto resume=/dev/mapper/rhel_rhel8u2--1-swap rd.lvm.lv=rhel_rhel8u2-1/root rd.lvm.lv=rhel_rhel8u2-1/swap nomodeset\n# ls -l /dev/fb*\nls: cannot access '/dev/fb*': No such file or directory\n~~~\nThe above said mitigation does not so effect for rhel6 kernel , and is only applicable for rhel7/8."}, "name": "CVE-2020-28974", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:5", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 5"}, {"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": "Will not fix", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Will not fix", "package_name": "kernel-alt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/a:redhat:enterprise_mrg:2", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise MRG 2"}], "public_date": "2020-11-09T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2020-28974\nhttps://nvd.nist.gov/vuln/detail/CVE-2020-28974"], "threat_severity": "Moderate"}

{}