#VU77254 Use-after-free in Linux kernel - CVE-2020-36694
Published: June 13, 2023
Vulnerability identifier: #VU77254
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2020-36694
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 the packet processing context, because the per-CPU sequence count is mishandled during concurrent iptables rules replacement. A local user with CAP_NET_ADMIN capability in an unprivileged namespace can execute arbitrary code with elevated privileges.
Remediation
Install updates from vendor's website.
External links
- https://syzkaller.appspot.com/bug?id=0c4fd9c6aa04ec116d01e915d3b186f71a212cb2
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc00bcaa589914096edef7fb87ca5cee4a166b5c
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10