#VU105090 Input validation error in Linux kernel - CVE-2025-21765

Vulnerability identifier: #VU105090

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21765

CWE-ID: CWE-20

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 perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation within the ip6_default_advmss() function in net/ipv6/route.c. A local user can perform a denial of service (DoS) attack.

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/3c8ffcd248da34fc41e52a46e51505900115fc2a
https://git.kernel.org/stable/c/4176a68b0db8fc74ac14fcd00ba8231371051dc2
https://git.kernel.org/stable/c/550ed693f47370502a71b85382e7f9e6417300b8
https://git.kernel.org/stable/c/713a40c892f40300d63691d9f85b2a23b48fe1e8
https://git.kernel.org/stable/c/84212387caadb211cd9dadd6fd5563bd37dc1f5e

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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.