CVE-2006-6171

CVE-2006-6171 is a high-severity vulnerability in Proftpd Project Proftpd with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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

Frequently asked questions

What is CVE-2006-6171?
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
How severe is CVE-2006-6171?
CVE-2006-6171 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2006-6171 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-6171?
CVE-2006-6171 affects Proftpd Project Proftpd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2006-6171?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2006-6171 published?
CVE-2006-6171 was published on 2006-11-30 and last updated on 2026-06-16.

References

Affected products (1)

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