CVE-2021-29155

medium

Description

An issue was discovered in the Linux kernel through 5.11.x. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory. Specifically, for sequences of pointer arithmetic operations, the pointer modification performed by the first operation is not correctly accounted for when restricting subsequent operations.

References

https://www.kernel.org

https://www.openwall.com/lists/oss-security/2021/04/18/4

https://lists.fedoraproject.org/archives/list/[email protected]/message/PAEQ3H6HKNO6KUCGRZVYSFSAGEUX23JL/

https://lists.fedoraproject.org/archives/list/[email protected]/message/CUX2CA63453G34C6KYVBLJXJXEARZI2X/

https://lists.fedoraproject.org/archives/list/[email protected]/message/XZASHZVCOFJ4VU2I3BN5W5EPHWJQ7QWX/

https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

Details

Source: MITRE

Published: 2021-04-20

Updated: 2022-04-19

Type: CWE-125

Risk Information

CVSS v2

Base Score: 2.1

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

Impact Score: 2.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3

Base Score: 5.5

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

Impact Score: 3.6

Exploitability Score: 1.8

Severity: MEDIUM