Exploited. On CISA's list since 2024-05-29.
Justice AV Solutions (JAVS) Viewer Installer Embedded Malicious Code Vulnerability
CVE-2024-4978 · Justice AV Solutions Viewer · Published 2024-05-23
How bad would it be?
8.7 out of 10
CVSS rates it high.
How likely is it to be used?
27%
Estimated chance of exploitation in the next 30 days, higher than 98% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 863 days ago (2024-06-19).
What CISA says to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Justice AV Solutions (JAVS) Viewer installer contains a malicious version of ffmpeg.exe, named fffmpeg.exe (SHA256: 421a4ad2615941b177b6ec4ab5e239c14e62af2ab07c6df1741e2a62223223c4). When run, this creates a backdoor connection to a malicious C2 server.
What the flaw is
Justice AV Solutions Viewer Setup 8.3.7.250-1 contains a malicious binary when executed and is signed with an unexpected authenticode signature. A remote, privileged threat actor may exploit this vulnerability to execute of unauthorized PowerShell commands.
From the NVD.
Learn this
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Understand the kind of weakness behind this flaw. These resources teach the weakness, rather than reproduce this specific CVE. Follow the vendor's advice above to fix the affected product.
CWE-506 · CISA KEV; NVD record: 9119a7d8-5eab-497f-8521-727c672e3725. We have not selected a close learning match for this label.
CWE is a catalogue of weakness types. Labels come from the sources shown and can differ or change. Resource matches reviewed 16 October 2026.
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Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.