#VU68301 Out-of-bounds write in Linux kernel - CVE-2021-3491
Published: October 13, 2022
Vulnerability identifier: #VU68301
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-3491
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to 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 used in mem_rw when reading
/proc/<PID>/mem. A local user can trigger a heap overflow and execute arbitrary code with elevated privileges.
Remediation
Install updates from vendor's website.