Is CVE-2010-20103 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2010-20103 being exploited in the wild.

How severe is CVE-2010-20103?

Critical severity, with a CVSS score of 9.8, published 20 August 2025.

Which products and versions are affected?

ProFTPD Project ProFTPD (Professional FTP Daemon) 1.3.3c.

Is there a fix for CVE-2010-20103?

A patch was published on 2010-12-02: Backdoored source removed from distribution sites Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2010-20103 attacked?

It is attacked over the network, in an operating system.

Am I affected by CVE-2010-20103?

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.

CVE-2010-20103: ProFTPD malicious backdoor in source distribution

CVE-2010-20103 · Severity: critical · CVSS 9.8 · Published 2025-08-20

ProFTPD is a widely used open-source file transfer server for Linux and Unix systems. A malicious backdoor was discovered in the official software download files distributed in late 2010, which allows an attacker to take complete control of the server. By sending a specific hidden command, an unauthorized person can remotely execute any instruction on the host computer with the highest possible privileges (root), potentially leading to data theft or full system compromise.

Technologies: Proftpd. Vendors: Proftpd.

Quick answers

Is CVE-2010-20103 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2010-20103 being exploited in the wild.
How severe is CVE-2010-20103?: Critical severity, with a CVSS score of 9.8, published 20 August 2025.
Which products and versions are affected?: ProFTPD Project ProFTPD (Professional FTP Daemon) 1.3.3c.
Is there a fix for CVE-2010-20103?: A patch was published on 2010-12-02: Backdoored source removed from distribution sites Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2010-20103 attacked?: It is attacked over the network, in an operating system.
Am I affected by CVE-2010-20103?: 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

A supply chain attack resulted in a malicious backdoor being embedded in the official ProFTPD 1.3.3c source archives (proftpd-1.3.3c.tar.gz and .bz2). The backdoor implements a hidden FTP command trigger that, when received by the daemon, bypasses authentication and executes arbitrary shell commands via a system call with root privileges. The vulnerability is reachable over the network without any prior authentication or user interaction. Security engineers should ensure that any installations from that period have been replaced with verified, clean versions of the software (1.3.3c or later maintenance releases).

Affected products

ProFTPD Project ProFTPD (Professional FTP Daemon) 1.3.3c

Timeline

2010-11-28: disclosed: Backdoored source distributed starting this date
2010-12-02: patched: Backdoored source removed from distribution sites
2011-01-04: advisory: Check Point published third-party advisory
2025-08-20: advisory: NVD publication date for CVE-2010-20103

References

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