CVE-2021-3491
Description
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/<PID>/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).
Related CPE's
References
CvssV3 impact
BaseSeverity | HIGH |
ConfidentialityImpact | HIGH |
AttackComplexity | LOW |
Scope | CHANGED |
AttackVector | LOCAL |
AvailabilityImpact | HIGH |
IntegrityImpact | HIGH |
PrivilegesRequired | LOW |
BaseScore | 8.8 |
VectorString | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
Version | 3.1 |
UserInteraction | NONE |
CvssV2 impact
AccessComplexity | LOW |
ConfidentialityImpact | COMPLETE |
AvailabilityImpact | COMPLETE |
IntegrityImpact | COMPLETE |
BaseScore | 7.2 |
VectorString | AV:L/AC:L/Au:N/C:C/I:C/A:C |
Version | 2.0 |
AccessVector | LOCAL |
Authentication | NONE |