#VU104966 Use-after-free in Linux kernel - CVE-2025-21710

Vulnerability identifier: #VU104966

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-2025-21710

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 tcp_select_window() function in net/ipv4/tcp_output.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/1dd823a46e25ffde1492c391934f69a9e5eb574f
https://git.kernel.org/stable/c/8c670bdfa58e48abad1d5b6ca1ee843ca91f7303
https://git.kernel.org/stable/c/b01e7ceb35dcb7ffad413da657b78c3340a09039
https://git.kernel.org/stable/c/b4055e2fe96f4ef101d8af0feb056d78d77514ff

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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.