CVE-2021-3491 — Incorrect Calculation of Buffer Size in Kernel

CWE-131 — Incorrect Calculation of Buffer SizeCWE-787 — Out-of-bounds WriteCWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer11 documents8 sources
Severity
8.8HIGHNVD
CNA7.8
EPSS
0.1%
top 81.42%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Linux KernelCanonical Ubuntu Linux
Timeline
PublishedJun 4
Latest updateMay 24

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//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…

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitability: 2.0 | Impact: 6.0

Affected Packages3 packages

▶CVEListV5linux/linux_kerneltrunk — v5.13-rc4+4
▶NVDlinux/linux_kernel5.7 — 5.10.37+2
▶Debianlinux/linux_kernel< 5.10.38-1+3

Also affects: Ubuntu Linux 20.04, 20.10, 21.04

Patches

Patch: git.kernel.org ↗Patch: www.openwall.com ↗Patch: git.kernel.org ↗

🔴Vulnerability Details

5
GHSA
GHSA-q4c9-gg27-f3pq: 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 value↗2022-05-24
▶
OSV
CVE-2021-3491: In io_add_buffers of io_uring↗2021-09-01
▶
CVEList
Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT bypass↗2021-06-04
▶
OSV
CVE-2021-3491: 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 value↗2021-06-04
▶
Kernel
io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers↗2021-05-05
▶

📋Vendor Advisories

5
Ubuntu
Linux kernel (OEM) vulnerabilities↗2021-05-11
▶
Ubuntu
Linux kernel vulnerabilities↗2021-05-11
▶
Ubuntu
Linux kernel vulnerabilities↗2021-05-11
▶
Red Hat
kernel: Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT bypass↗2021-05-11
▶
Debian
CVE-2021-3491: linux - The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be ...↗2021
▶
CVE-2021-3491 — Incorrect Calculation of Buffer Size | cvebase