#VU67642 Out-of-bounds write in HarfBuzz - CVE-2021-45931

Vulnerability identifier: #VU67642

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-2021-45931

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
HarfBuzz
Other software / Other software solutions

Vendor: Freedesktop.org

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input within the hb_bit_set_invertible_t::set() function. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger an out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

HarfBuzz: 2.0.0 - 2.9.0

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External links
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/harfbuzz/OSV-2021-1159.yaml
https://github.com/harfbuzz/harfbuzz/commit/d3e09bf4654fe5478b6dbf2b26ebab6271317d81
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=37425
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5A7TCR2MY46YK3NHQZB3SLESUH354IEA/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DI6247WOAKB46CZZ6SCDSJVWWCW3GMZH/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EAIZKL4O67FN2CWJYHYKZEMNYWNWO3D/
https://security.gentoo.org/glsa/202209-11

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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.