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).
Published 2021-06-04 02:15:07
Updated 2021-09-14 14:31:37
View at NVD,   CVE.org
Vulnerability category: Memory Corruption

Exploit prediction scoring system (EPSS) score for CVE-2021-3491

Probability of exploitation activity in the next 30 days: 0.05%

Percentile, the proportion of vulnerabilities that are scored at or less: ~ 19 % EPSS Score History EPSS FAQ

CVSS scores for CVE-2021-3491

Base Score Base Severity CVSS Vector Exploitability Score Impact Score Score Source
7.2
HIGH AV:L/AC:L/Au:N/C:C/I:C/A:C
3.9
10.0
NIST
8.8
HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
2.0
6.0
NIST
7.8
HIGH CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
1.1
6.0
Canonical Ltd.

CWE ids for CVE-2021-3491

  • The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
    Assigned by: security@ubuntu.com (Secondary)
  • The product writes data past the end, or before the beginning, of the intended buffer.
    Assigned by: nvd@nist.gov (Primary)

References for CVE-2021-3491

Products affected by CVE-2021-3491

This web site uses cookies for managing your session, storing preferences, website analytics and additional purposes described in our privacy policy.
By using this web site you are agreeing to CVEdetails.com terms of use!