#VU87849 Infinite loop in xz - CVE-2021-29482

Vulnerability identifier: #VU87849

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-2021-29482

CWE-ID: CWE-835

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
xz
Universal components / Libraries / Programming Languages & Components

Vendor: ulikunitz

Description

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

The vulnerability exists due the function readUvarint used to read the xz container format may not terminate a loop providing malicious input. A remote attacker can consume all available system resources and cause denial of service conditions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

xz: 0.1 - 0.5.7

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External links
https://github.com/ulikunitz/xz/security/advisories/GHSA-25xm-hr59-7c27
https://github.com/ulikunitz/xz/commit/69c6093c7b2397b923acf82cb378f55ab2652b9b

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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.