#VU56713 Heap-based buffer overflow in ytnef - CVE-2021-3404

Vulnerability identifier: #VU56713

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-2021-3404

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
ytnef
Other software / Other software solutions

Vendor: Yeraze (Randall Hand)

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the SwapWord() function in lib/ytnef.c. A remote attacker can trick the victim to open a specially crafted file, trigger a heap-based buffer 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

ytnef: 1.7 - 1.9.3

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1926965
https://github.com/Yeraze/ytnef/issues/86

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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.