# CVE-2015-3306: ProFTPD improper access control in SITE commands

Source: https://junglewise.ai/threats/cve-2015-3306-proftpd-improper-access-control-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-08. Updated: 2026-10-08  
License: CC BY 4.0 with a link back

CVE-2015-3306 · Severity: critical · Exploited in the wild · Published 2026-10-08

ProFTPD is an FTP server that provides file transfer services to clients. This vulnerability allows remote attackers to bypass access controls and read or write arbitrary files on the server using specially crafted SITE CPFR and SITE CPTO commands, potentially exposing sensitive data or allowing unauthorized file modification.

Technologies: [Proftpd](https://junglewise.ai/threats/technologies/proftpd). Vendors: [Proftpd](https://junglewise.ai/threats/vendors/proftpd).

## Quick answers

**Is CVE-2015-3306 exploited in the wild?** Yes. CVE-2015-3306 is known to be exploited in the wild, first recorded on 8 October 2026. Treat it as urgent.

**How severe is CVE-2015-3306?** Critical severity, published 8 October 2026.

**Which products and versions are affected?** ProFTPD ProFTPD.

**Is there a fix for CVE-2015-3306?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2015-3306 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2015-3306?** Check whether you run Proftpd. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

ProFTPD fails to properly validate access controls when processing SITE CPFR (copy from) and SITE CPTO (copy to) commands, allowing remote attackers to bypass intended file access restrictions. The vulnerability requires network access to an FTP server but no prior authentication. An attacker can exploit this to read arbitrary files from the system or write malicious files, achieving unauthorized information disclosure or system compromise.

## Affected products

- ProFTPD ProFTPD

## Timeline

- 2026-10-08: disclosed
- exploited: reported exploited in wild

## Related threats

- [ProFTPD mod_copy symlink traversal in SITE COPY](https://junglewise.ai/threats/cve-2026-119364-proftpd-through-1-3-9e-and-1-3-10rc1-through-1-3-10rc4-contains)
- [ProFTPD buffer overflow in mod_rewrite utf8trans](https://junglewise.ai/threats/cve-2026-119146-proftpd-before-1-3-9e-and-1-3-10rc5-contains-a-buffer-overflow)
- [ProFTPD mod_sql SQL injection in logging pipeline](https://junglewise.ai/threats/cve-2026-42167-proftpd-mod-sql-sql-injection-in-logging-pipeline)
- [ProFTPD malicious backdoor in source distribution](https://junglewise.ai/threats/cve-2010-20103-proftpd-malicious-backdoor-in-source-distribution)