#VU106632 Use-after-free in Linux kernel - CVE-2025-21969

Vulnerability identifier: #VU106632

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-2025-21969

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 l2cap_get_ident(), l2cap_send_cmd(), l2cap_conn_del(), l2cap_conn_free(), l2cap_recv_reset() and l2cap_recv_acldata() functions in net/bluetooth/l2cap_core.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.12, 6.12.1, 6.12.2, 6.12.3, 6.12.4, 6.12.5, 6.12.6, 6.12.7, 6.12.8, 6.12.9, 6.12.10, 6.12.11, 6.12.12, 6.12.13, 6.12.14, 6.12.15, 6.12.16, 6.12.17, 6.12.18, 6.12.19

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External links
https://git.kernel.org/stable/c/7790a79c6fce8d5d552bc64f5c82819f719e4f28
https://git.kernel.org/stable/c/b4f82f9ed43aefa79bec2504ae8c29be0c0f5d1d
https://git.kernel.org/stable/c/c96cce853542b3b13da3738f35ef1be8cfcc9d1d
https://git.kernel.org/stable/c/f8094625a591eeb0b75b1bd9e713fac1d93f5ca9
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.20

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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.