UBUNTU-CVE-2021-33200
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.
02 / AFFECTED SOFTWARE
Affected packages
23 explicit affected versions
6 explicit affected versions
10 explicit affected versions
44 explicit affected versions
16 explicit affected versions
4 explicit affected versions
38 explicit affected versions
13 explicit affected versions
12 explicit affected versions
33 explicit affected versions
43 explicit affected versions
10 explicit affected versions
50 explicit affected versions
7 explicit affected versions
9 explicit affected versions
6 explicit affected versions
12 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://ubuntu.com/security/CVE-2021-33200
- https://ubuntu.com/security/notices/USN-4983-1
- https://ubuntu.com/security/notices/USN-4997-1
- https://ubuntu.com/security/notices/USN-4997-2
- https://ubuntu.com/security/notices/USN-4999-1
- https://ubuntu.com/security/notices/USN-5000-1
- https://ubuntu.com/security/notices/USN-5000-2
- https://ubuntu.com/security/notices/USN-5018-1
- https://www.cve.org/CVERecord?id=CVE-2021-33200
- https://www.openwall.com/lists/oss-security/2021/05/27/1