#VU51548 Resource exhaustion in Linux kernel - CVE-2021-20265

Vulnerability identifier: #VU51548

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-2021-20265

CWE-ID: CWE-400

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 application does not properly control consumption of internal resources in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. A local user can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 4.5, 4.5

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1908827
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa0dc04df259ba2df3ce1920e9690c7842f8fa4b

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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.