#VU103591 Improper locking in Linux kernel - CVE-2025-21681

Vulnerability identifier: #VU103591

Vulnerability risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:U/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21681

CWE-ID: CWE-667

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 locking within the do_output() function in net/openvswitch/actions.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

---

External links
https://git.kernel.org/stable/c/47e55e4b410f7d552e43011baa5be1aab4093990
https://git.kernel.org/stable/c/82f433e8dd0629e16681edf6039d094b5518d8ed
https://git.kernel.org/stable/c/ea966b6698785fb9cd0fdb867acd91b222e4723f
https://git.kernel.org/stable/c/ea9e990356b7bee95440ba0e6e83cc4d701afaca

---

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.