#VU75206 Uncontrolled Recursion in Linux kernel - CVE-2020-36691

Vulnerability identifier: #VU75206

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-2020-36691

CWE-ID: CWE-674

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 uncontrolled recursion in lib/nlattr.c. A local user can use a nested Netlink policy with a back reference to crash the kernel.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.8.0, 5.8.0

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External links
https://github.com/torvalds/linux/commit/7690aa1cdf7c4565ad6b013b324c28b685505e24
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8

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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.