#VU62375 Integer overflow in klibc - CVE-2021-31870

Vulnerability identifier: #VU62375

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-31870

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 execute arbitrary code on the target system.

The vulnerability exists due to integer overflow in the calloc() function. A remote attacker can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

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=292650f04c2b5348b4efbad61fb014ed09b4f3f2
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.