| CVE-2021-3491 | Date: (C)2021-06-04 (M)2024-04-26 |
The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc//mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).
CVSS Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 8.8 | CVSS Score : 7.2 |
| Exploit Score: 2.0 | Exploit Score: 3.9 |
| Impact Score: 6.0 | 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: CHANGED | Integrity: COMPLETE |
| Confidentiality: HIGH | Availability: COMPLETE |
| Integrity: HIGH | |
| Availability: HIGH | |
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