CVE-2021-33200 Information

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.

CVSS Vector

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

Reference

https://www.openwall.com/lists/oss-security/2021/05/27/1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JJCABL43FT3FKRX5DBPZG25FNKR6CEK4/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7LR3OKKPHIBGOMHN476CMLW2T7UG53QX/ https://security.netapp.com/advisory/ntap-20210706-0004/

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8