#VU103741 Use-after-free in Linux kernel - CVE-2025-21693

Vulnerability identifier: #VU103741

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:U/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21693

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: 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 zswap_pool_create(), zswap_cpu_comp_prepare(), zswap_cpu_comp_dead(), zswap_compress() and zswap_decompress() functions in mm/zswap.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/12dcb0ef540629a281533f9dedc1b6b8e14cfb65
https://git.kernel.org/stable/c/8d29ff5d50304daa41dc3cfdda4a9d1e46cf5be1

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.