#VU104073 Use-after-free in Linux kernel - CVE-2025-21703

Vulnerability identifier: #VU104073

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-2025-21703

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 net/sched/sch_netem.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

---

External links
https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5
https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83
https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71
https://git.kernel.org/stable/c/839ecc583fa00fab785fde1c85a326743657fd32

---

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.