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CVE-2015-3306: ProFTPD Improper Access Control Vulnerability

CVE-2015-3306 is rated critical with a CVSS v3.1 base score of 10.0 and affects ProFTPD ProFTPD, along with 4 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-10-08, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v3.1 10.0: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-284: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected products

Proftpd: 1.3.5
Fedoraproject: 20; 21; 22
Debian Linux: 7.0; 8.0; 9.0
Opensuse Tumbleweed: all versions listed by NVD
Suse Linux Enterprise Server: 15 sp7