Use-after-free in Linux kernel - CVE-2021-47505
Published: May 30, 2024 / Updated: May 14, 2025
Vulnerability identifier: #VU90051
CSH Severity: 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-2021-47505
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 within the POLLFREE() function in include/uapi/asm-generic/poll.h, within the aio_poll(), aio_poll_complete_work(), aio_poll_cancel(), aio_poll_wake() and aio_poll_queue_proc() functions in fs/aio.c. A local user can escalate privileges on the system.
Remediation
Install update from vendor's website.
External links
- https://git.kernel.org/stable/c/321fba81ec034f88aea4898993c1bf15605c023f
- https://git.kernel.org/stable/c/4105e6a128e8a98455dfc9e6dbb2ab0c33c4497f
- https://git.kernel.org/stable/c/47ffefd88abfffe8a040bcc1dd0554d4ea6f7689
- https://git.kernel.org/stable/c/60d311f9e6381d779d7d53371f87285698ecee24
- https://git.kernel.org/stable/c/50252e4b5e989ce64555c7aef7516bdefc2fea72
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.221
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.85
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.8
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.165