Vulnerability identifier: #VU54224

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3517

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Libxml2
Universal components / Libraries / Libraries used by multiple products

Vendor: Gnome Development Team

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input in the xml entity encoding functionality. A remote attacker can create a specially crafted file, trick the victim into opening it using the affected software, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Libxml2: 2.9.0 - 2.9.10

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1954232
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/
http://lists.debian.org/debian-lts-announce/2021/05/msg00008.html
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6YIZAFDGX6/

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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.