#VU54222 Use-after-free in Libxml2 - CVE-2021-3516

Vulnerability identifier: #VU54222

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-3516

CWE-ID: CWE-416

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 use-after-free error in xmllint. A remote attacker can use a specially crafted file to execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Libxml2: 2.9.0 - 2.9.10

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1954225
https://gitlab.gnome.org/GNOME/libxml2/-/commit/1358d157d0bd83be1dfe356a69213df9fac0b539
https://gitlab.gnome.org/GNOME/libxml2/-/issues/230
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/
https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html
https://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.