#VU56712 Double Free in ytnef - CVE-2021-3403

Vulnerability identifier: #VU56712

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-2021-3403

CWE-ID: CWE-415

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 double free error within the TNEFSubjectHandler() function in lib/ytnef.c. A remote attacker can trick the victim to open a specially crafted file, trigger a double free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update 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=1926967
https://github.com/Yeraze/ytnef/issues/85

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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.