CVE-2021-33909

high

Description

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

References

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4

https://github.com/torvalds/linux/commit/8cae8cd89f05f6de223d63e6d15e31c8ba9cf53b

https://www.openwall.com/lists/oss-security/2021/07/20/1

https://lists.debian.org/debian-lts-announce/2021/07/msg00016.html

https://lists.debian.org/debian-lts-announce/2021/07/msg00015.html

https://lists.debian.org/debian-lts-announce/2021/07/msg00014.html

https://www.debian.org/security/2021/dsa-4941

http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/Z4UHHIGISO3FVRF4CQNJS4IKA25ATSFU/

http://www.openwall.com/lists/oss-security/2021/07/22/7

http://packetstormsecurity.com/files/163671/Kernel-Live-Patch-Security-Notice-LSN-0079-1.html

https://security.netapp.com/advisory/ntap-20210819-0004/

http://www.openwall.com/lists/oss-security/2021/08/25/10

http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html

http://www.openwall.com/lists/oss-security/2021/09/17/2

http://www.openwall.com/lists/oss-security/2021/09/17/4

http://www.openwall.com/lists/oss-security/2021/09/21/1

http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html

https://www.oracle.com/security-alerts/cpujan2022.html

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0015

Details

Source: MITRE

Published: 2021-07-20

Updated: 2022-08-10

Type: CWE-120

Risk Information

CVSS v2

Base Score: 7.2

Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Impact Score: 10

Exploitability Score: 3.9

Severity: HIGH

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 1.8

Severity: HIGH