#VU62376 Integer overflow in klibc - CVE-2021-31871

Vulnerability identifier: #VU62376

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-31871

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
klibc
Operating systems & Components / Operating system package or component

Vendor: git.kernel.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to integer overflow in the cpio command. A remote attacker can pass specially crafted data to the application, trigger integer overflow and cause a denial of service condition on the target system.

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

Vulnerable software versions

klibc: before 2.0.9

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External links
https://kernel.org/pub/linux/libs/klibc/2.0/
https://lists.zytor.com/archives/klibc/2021-April/004593.html
https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=2e48a12ab1e30d43498c2d53e878a11a1b5102d5
https://www.openwall.com/lists/oss-security/2021/04/30/1
https://lists.debian.org/debian-lts-announce/2021/06/msg00025.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.