#VU63838 Use-after-free in Linux kernel - CVE-2021-4203
Published: May 31, 2022
Vulnerability identifier: #VU63838
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-2021-4203
CWE-ID: CWE-416
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 a use-after-free error in sock_getsockopt() function in net/core/sock.c due to SO_PEERCRED and SO_PEERGROUPS race with listen() function (and connect() function) in the Linux kernel. A local user can exploit the use-after-free error and crash the system or escalate privileges on the system.
Remediation
Install updates from vendor's website.
External links
- https://lore.kernel.org/netdev/20210929225750.2548112-1-eric.dumazet@gmail.com/T/
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2230&can=7&q=modified-after%3Atoday-30&sort=-modified&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified%20Cve&cells=tiles&redir=1
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814
- https://bugzilla.redhat.com/show_bug.cgi?id=2036934