Use after free in Linux kernel - CVE-2020-25669
Published: May 26, 2021 / Updated: February 24, 2023
Vulnerability identifier: #VU92762
CSH Severity: Low
CVSS v4.0: 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-2020-25669
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to execute arbitrary code.
A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed. Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still an alias in sunkbd_reinit causing Use After Free.
How to mitigate CVE-2020-25669
Install update from vendor's repository.
Sources
- https://github.com/torvalds/linux/commit/77e70d351db7de07a46ac49b87a6c3c7a60fca7e
- https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
- http://www.openwall.com/lists/oss-security/2020/11/20/5
- https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
- http://www.openwall.com/lists/oss-security/2020/11/05/2
- https://www.openwall.com/lists/oss-security/2020/11/05/2,
- https://www.openwall.com/lists/oss-security/2020/11/20/5,
- https://security.netapp.com/advisory/ntap-20210702-0006/