#VU103023 NULL pointer dereference in Linux kernel - CVE-2025-21636

Vulnerability identifier: #VU103023

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-2025-21636

CWE-ID: CWE-476

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 NULL pointer dereference within the proc_sctp_do_udp_port() function in net/sctp/sysctl.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/284a221f8fa503628432c7bb5108277c688c6ffa
https://git.kernel.org/stable/c/44ee8635922b6eb940faddb961a8347c6857d722
https://git.kernel.org/stable/c/6259d2484d0ceff42245d1f09cc8cb6ee72d847a
https://git.kernel.org/stable/c/bcf8c60074e81ed2ac2d35130917175a3949c917

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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.