Overview
CVE-2015-3306 has been added to the CISA Known Exploited Vulnerabilities catalog. Published on May 18, 2015. Threat actors are actively exploiting this vulnerability in real-world attacks.
The mod_copy module in ProFTPD 1.
Threat Intelligence
| Metric | Value |
|---|---|
| CVE ID | CVE-2015-3306 |
| Severity | HIGH |
| CVSS Score | 0.0/10 |
| CISA KEV | ✅ Yes — Actively Exploited |
| KEV Date Added | October 08, 2026 |
| Remediation Deadline | October 11, 2026 |
| EPSS Score | 96.8% exploit probability |
| EPSS Percentile | Top 99% of all CVEs |
Why This Matters
This vulnerability has been added to the CISA Known Exploited Vulnerabilities (KEV) catalog, which means threat actors are actively exploiting it in real-world attacks.
Federal agencies are required to remediate by October 11, 2026. All organizations should treat this deadline as a strong recommendation.
CISA Notes: This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: http://www.proftpd.org/ ; https://lists.debian.org/debian-security-announce/2015/msg00154.html ; https://lists.opensuse.org/archives/list/updates@lists.opensuse.org/message/WE6YZRG5UVXMGQ7IVDRYBPIWV4M6UUGM/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2015-3306
Exploit Prediction (EPSS)
The FIRST EPSS model rates this vulnerability at 96.8% exploit probability (Very High). This places it in the top 99% of all known CVEs by likelihood of exploitation in the next 30 days.
EPSS (Exploit Prediction Scoring System) uses real-world exploit data and machine learning to predict whether a vulnerability will be exploited. A high EPSS score is a strong signal to prioritize remediation.
Recommended Actions
- Verify exposure — Determine if your environment uses the affected software.
- Apply patches — Update to the latest version as soon as a fix is available.
- Monitor for compromise — Check logs for unusual activity.
- Meet the deadline — CISA recommends remediation by October 11, 2026.
References
CVE data aggregated from the National Vulnerability Database (NVD), CISA Known Exploited Vulnerabilities catalog, and FIRST EPSS. Analysis updated as new intelligence becomes available. Last updated: 2026-10-08.