Justice AV Solutions (JAVS) Viewer Installer Embedded Malicious Code Vulnerability
Justice AV Solutions / Viewer
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.
- CVE identifier
- CVE-2024-4978
- Added to KEV
- May 29, 2024
- CISA catalog dueDate
- Jun 19, 2024
The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.
Publisher's required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.
Keep the signals separate.
- Ransomware use, as reported by CISA
- Unknown
- CVSS severity
- Not supplied by KEV
- EPSS probability
- 26.94%
EPSS score date: 2026-09-27T12:00:21Z. Percentile: 97.97%. Model version: v2026.06.15.
A dated estimate of exploitation probability over the following 30 days, not a severity score or a probability of a breach in your environment.
Inspect the EPSS source ↗“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.
Source notes
Please follow the vendor’s instructions as outlined in the public statements at https://www.rapid7.com/blog/post/2024/05/23/cve-2024-4978-backdoored-justice-av-solutions-viewer-software-used-in-apparent-supply-chain-attack#remediation and https://www.javs.com/downloads; https://nvd.nist.gov/vuln/detail/CVE-2024-4978
Source & freshness
Source updated: Sep 27, 2026, 9:30 PM UTC
Successfully checked: Sep 27, 2026, 11:50 PM UTC
This snapshot is older than 36 hours. Check current publisher guidance.
Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.