| CVE-2021-3490 | Date: (C)2021-06-04 (M)2024-04-26 |
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).
CVSS Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 7.8 | CVSS Score : 7.2 |
| Exploit Score: 1.8 | Exploit Score: 3.9 |
| Impact Score: 5.9 | Impact Score: 10.0 |
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| CVSS V3 Metrics: | CVSS V2 Metrics: |
| Attack Vector: LOCAL | Access Vector: LOCAL |
| Attack Complexity: LOW | Access Complexity: LOW |
| Privileges Required: LOW | Authentication: NONE |
| User Interaction: NONE | Confidentiality: COMPLETE |
| Scope: UNCHANGED | Integrity: COMPLETE |
| Confidentiality: HIGH | Availability: COMPLETE |
| Integrity: HIGH | |
| Availability: HIGH | |
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