CVE-2010-20103

Proftpd vulnerability

9.8 CRITICALPublic exploitEPSS 5.09%

Published20 Aug 2025

Description

A malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and December 2, 2010. The backdoor implements a hidden FTP command trigger that, when invoked, causes the server to execute arbitrary shell commands with root privileges. This allows remote, unauthenticated attackers to run any OS command on the FTP server host.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Proftpd1.3.3

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

https://advisories.checkpoint.com/defense/advisories/public/2011/cpai-2010-151.html/Third Party Advisory
https://github.com/proftpd/proftpdProduct
https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/unix/ftp/proftpd_133c_backdoor.rbExploitThird Party Advisory
https://web.archive.org/web/20111107212129/http://rsync.proftpd.org/Release Notes
https://www.exploit-db.com/exploits/15662ExploitVDB Entry
https://www.exploit-db.com/exploits/16921ExploitVDB Entry
https://www.vulncheck.com/advisories/proftpd-backdoor-command-executionThird Party Advisory
http://www.proftpd.org/Product

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2010-20103 being actively exploited?

CVE-2010-20103 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 5.09%.

How severe is CVE-2010-20103?

CVE-2010-20103 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 5.09% probability of exploitation.

Which products are affected by CVE-2010-20103?

Affected products include Proftpd.

How do I fix CVE-2010-20103?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2010-20103 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.