#VU23818 NULL pointer dereference in Linux kernel - CVE-2019-20054

Vulnerability identifier: #VU23818

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-2019-20054

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 a NULL pointer dereference error in the Linux kernel before 5.0.6 in drop_sysctl_table() in fs/proc/proc_sysctl.c, related to put_links, aka CID-23da9588037e. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.0 - 5.0.5

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External links
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.11
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.6
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23da9588037ecdd4901db76a5b79a42b529c4ec3
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=89189557b47b35683a27c80ee78aef18248eefb4

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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.