CVE-2021-33200

high

Description

kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.

References

https://www.openwall.com/lists/oss-security/2021/05/27/1

https://lists.fedoraproject.org/archives/list/[email protected]/message/JJCABL43FT3FKRX5DBPZG25FNKR6CEK4/

https://lists.fedoraproject.org/archives/list/[email protected]/message/7LR3OKKPHIBGOMHN476CMLW2T7UG53QX/

https://security.netapp.com/advisory/ntap-20210706-0004/

Details

Source: MITRE

Published: 2021-05-27

Updated: 2022-05-13

Type: CWE-787

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