#VU17804 Use-after-free in Linux kernel - CVE-2019-8912

Vulnerability identifier: #VU17804

Vulnerability risk: Low

CVSSv4.0: 5.4 [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:P/U:Clear]

CVE-ID: CVE-2019-8912

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 attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to the af_alg_release() function, as defined in the crypto/af_alg.c source code file of the affected software, fails to set a NULL value for a certain structure member. A local attacker can access the system and execute an application that submits malicious input to the affected software and trigger a use-after-free condition in the sockfs_setattr function, resulting in a DoS condition

Mitigation
Cybersecurity Help is currently unaware of any official solution to address the vulnerability.

Vulnerable software versions

Linux kernel: 4.19 - 4.19.24, 4.20.1 - 4.20.10

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External links
https://patchwork.ozlabs.org/patch/1042902/

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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. However, proof of concept for this vulnerability is available.