Use-after-free in Linux kernel net

1) Use-after-free

EUVDB-ID: #VU90223

Risk: Low

CVSSv3.1: 7.7 [AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-47131

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

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 tls_ctx_create() function in net/tls/tls_main.c, within the tls_validate_xmit_skb() function in net/tls/tls_device_fallback.c, within the tls_device_gc_task(), tls_device_rx_resync_new_rec(), tls_device_decrypted() and tls_device_down() functions in net/tls/tls_device.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

http://git.kernel.org/stable/c/f1d4184f128dede82a59a841658ed40d4e6d3aa2
http://git.kernel.org/stable/c/0f1e6fe66977a864fe850522316f713d7b926fd9
http://git.kernel.org/stable/c/c55dcdd435aa6c6ad6ccac0a4c636d010ee367a4

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.