CVE-2020-27171

medium

Description

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

References

https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/patch/?id=10d2bb2e6b1d8c4576c56a748f697dbeb8388899

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8

https://www.openwall.com/lists/oss-security/2021/03/19/3

https://lists.fedoraproject.org/archives/list/[email protected]/message/QRTPQE73ANG7D6M4L4PK5ZQDPO4Y2FVD/

https://lists.fedoraproject.org/archives/list/[email protected]/message/FB6LUXPEIRLZH32YXWZVEZAD4ZL6SDK2/

http://www.openwall.com/lists/oss-security/2021/03/24/5

https://lists.fedoraproject.org/archives/list/[email protected]/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG/

https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html

http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html

Details

Source: MITRE

Published: 2021-03-20

Updated: 2022-07-30

Type: CWE-193

Risk Information

CVSS v2

Base Score: 3.6

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

Impact Score: 4.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3

Base Score: 6

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

Impact Score: 5.2

Exploitability Score: 0.8

Severity: MEDIUM