Antivirus apps are there to protect you – Cisco's ClamAV has a heckuva flaw

Antivirus software is supposed to be an important part of an organization's defense against the endless tide of malware.

Cisco's open source ClamAV can fill that role – once you patch the 9.8/10 rated arbitrary code execution flaw the networking giant revealed on Wednesday.

"A vulnerability in the HFS+ partition file parser of ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier could allow an unauthenticated, remote attacker to execute arbitrary code," states Cisco's security advisory, which identifies the issue as CVE-2023-20032.

"This vulnerability is due to a missing buffer size check that may result in a heap buffer overflow write," the document elaborates. "An attacker could exploit this vulnerability by submitting a crafted HFS+ partition file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to execute arbitrary code with the privileges of the ClamAV scanning process, or else crash the process, resulting in a denial of service (DoS) condition."

ClamAV's blog reveals a second flaw in the software: CVE-2023-20052.

Both are patched in version 1.01 of the application, available here.

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But fixing ClamAV is not the end of the story. Addressing the faulty file parser also requires updates to other Cisco products, including the Secure Web Appliance hardware. The Secure Endpoint Private Cloud also needs a fix, as does Cisco's Secure Endpoint product (formerly known as Advanced Malware Protection for Endpoints) for Linux, Windows, and macOS.

Thankfully, Cisco is not aware of "any public announcements or malicious use of the vulnerability that is described in this advisory."

But what with ClamAV being free and open source, these flaws will likely be a target that miscreants and criminals won't ignore for long.

So while the lack of exploits means this may not be a weekend-killer, swift action – not clamming up about it – looks wise. ®