CVE-2021-3490
Severity CVSS v4.0:
Pending analysis
Type:
CWE-125
Out-of-bounds Read
Publication date:
04/06/2021
Last modified:
14/09/2021
Description
The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).
Impact
Base Score 3.x
7.80
Severity 3.x
HIGH
Base Score 2.0
7.20
Severity 2.0
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.10 (including) | 5.10.37 (excluding) |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.11 (including) | 5.11.21 (excluding) |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.12 (including) | 5.12.4 (excluding) |
| cpe:2.3:o:linux:linux_kernel:5.13:-:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | ||
| cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* | ||
| cpe:2.3:o:canonical:ubuntu_linux:20.10:*:*:*:*:*:*:* | ||
| cpe:2.3:o:canonical:ubuntu_linux:21.04:*:*:*:*:*:*:* |
To consult the complete list of CPE names with products and versions, see this page
References to Advisories, Solutions, and Tools
- http://packetstormsecurity.com/files/164015/Linux-eBPF-ALU32-32-bit-Invalid-Bounds-Tracking-Local-Privilege-Escalation.html
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=049c4e13714ecbca567b4d5f6d563f05d431c80e
- https://security.netapp.com/advisory/ntap-20210716-0004/
- https://ubuntu.com/security/notices/USN-4949-1
- https://ubuntu.com/security/notices/USN-4950-1
- https://www.openwall.com/lists/oss-security/2021/05/11/11
- https://www.zerodayinitiative.com/advisories/ZDI-21-606/



