CVE-2021-3491

Advisory lineage Upstream: 0 Downstream: 24
Modified
Published: 04 Jun 2021, 01:40
Last modified:16 Sept 2024, 22:09

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.8 HIGH
v3.1 (nvd)
EPSS Score
0.06% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

04 Jun 2021, 01:40
Published
Vulnerability first disclosed
16 Sept 2024, 22:09
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: 7.8CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
  • v2.0•HIGH•Score: 7.2AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.06%• Percentile: 19%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

  • CWE-131•Incorrect Calculation of Buffer Size

    The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.

Affected Systems

  • canonical•ubuntu_linux

    20.04 | 20.10 | 21.04

  • linux•linux_kernel

    ≥ 5.7, < 5.10.37 | ≥ 5.11, < 5.11.21 | ≥ 5.12, < 5.12.4 | ≥ trunk, < v5.13-rc4 | ≥ linux-5.12.y, < v5.12.4 | ≥ linux-5.11.y, < v5.11.21 | ≥ linux-5.10.y, < v5.10.37 | ≥ v5.7-rc1, < 5.7*

References (6)