#VU106955 Use-after-free in Linux kernel - CVE-2025-21999

Vulnerability identifier: #VU106955

Vulnerability risk: Low

CVSSv4.0: 5.9 [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-2025-21999

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 proc_get_inode() function in fs/proc/inode.c, within the proc_create_reg(), proc_create_seq_private() and proc_create_single_data() functions in fs/proc/generic.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.12 - 6.12.20

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External links
https://git.kernel.org/stable/c/63b53198aff2e4e6c5866a4ff73c7891f958ffa4
https://git.kernel.org/stable/c/64dc7c68e040251d9ec6e989acb69f8f6ae4a10b
https://git.kernel.org/stable/c/654b33ada4ab5e926cd9c570196fefa7bec7c1df
https://git.kernel.org/stable/c/966f331403dc3ed04ff64eaf3930cf1267965e53
https://git.kernel.org/stable/c/ede3e8ac90ae106f0b29cd759aadebc1568f1308
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.21

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Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?