// CVE

CVE-2015-3306

Critical 10.0 Exploited (KEV)

n/a n/a

10.0CVSS
99%EPSS
YesCISA KEV

Summary

The mod_copy module in ProFTPD 1.3.5 allows remote attackers to read and write to arbitrary files via the site cpfr and site cpto commands.

Published: 2015-05-18 · In KEV since: 2026-10-08

Analysis

🔴 Critical — actively exploited

Weakness: Improper Access Control (CWE-284). Fails to properly restrict who can do what.

How it's exploited: Exploitable over the network (internet-reachable), unauthenticated, no user interaction, and with low complexity. The flaw can pivot to other components (scope changed).

⚠️ Critical combo: remote, unauthenticated and no interaction → trivial to automate.

Impact: Full compromise (confidentiality, integrity and availability).

Status: Active exploitation confirmed by CISA (KEV).

How to defend:
  • Patch now: it is in CISA's actively-exploited catalog (KEV), with a deadline.
  • Reduce exposure: keep it off the internet; firewall, VPN or network segmentation.
  • Detect: turn this CVE into detection rules.

MITRE ATT&CK technique: T1190 · Exploit Public-Facing Application

Practice it in the arsenal: WAF Bypass

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

The vector encodes how it's exploited (translated above, in the analysis). Break it down in the CVSS tool →

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Sources: CISA KEV · EPSS · FIRST.org · NVD. Analysis derived from the CVSS vector and exploitation status (no AI). Informational; always verify against the vendor's official advisory.