DEBIAN-CVE-2021-3491

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2021-3491
Published: 04 Jun 2021, 02:15
Last modified:28 Apr 2026, 20:22

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.8 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

04 Jun 2021, 02:15
Published
Vulnerability first disclosed
28 Apr 2026, 20:22
Last Modified
Vulnerability information updated

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).

CVSS Metrics

  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected Systems

  • debian•linux

    < 5.10.38-1 | < 5.10.38-1 | < 5.10.38-1 | < 5.10.38-1

References (1)