CVE-2006-6171

What it is

ProFTPD 1.3.0a and earlier does not properly set the buffer size limit when CommandBufferSize is specified in the configuration file, which leads to an off-by-two buffer underflow. NOTE: in November 2006, the role of CommandBufferSize was originally associated with CVE-2006-5815, but this was an error stemming from a vague initial disclosure. NOTE: ProFTPD developers dispute this issue, saying that the relevant memory location is overwritten by assignment before further use within the affected function, so this is not a vulnerability

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

10.2% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2006-11-30 15:28 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 22:32 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 10.2% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2006-11-30 15:28 UTC

Last modified

2026-06-16 22:32 UTC

Exploit probability

10.2% · EPSS, next 30 days

Record status

Modified

Affected

• Proftpd Project Proftpd ≤ 1.3.0a

Attack profile CVSS 2.0 · 7.5

Attack vector

Network

Complexity

Low

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2006-6171.md and follow it. Check whether this project is affected by CVE-2006-6171. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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