CVE-2012-5905: Buffer overflow in KnFTPd 1.0.0 allows remote authenticated users to cause a denial of service (crash) via a l

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MEDIUM 4.0DOWNGRADE

CVE-2012-5905 is a medium-severity flaw (CVSS 4.0) affecting knftpd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in KnFTPd 1.0.0 allows remote authenticated users to cause a denial of service (crash) via a long string in a FEAT command.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.0 (Medium)
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Weakness	CWE-119
Published	2012-11-17
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: elif keir

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2012-11-17 21:55 UTCPublished CVE record published
2026-06-16 23:47 UTCUpdated Record last modified

elif keir knftpd DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy knftpd || rpm -q knftpd || knftpd --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison knftpd sudo apt install knftpd=<VERSION_BEFORE_1.0.0> sudo apt-mark hold knftpd

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list knftpd sudo dnf downgrade knftpd-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add knftpd

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: KnFTPd 1.0.0 - 'FEAT' Denial of Service (PoC)

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2012-5905?

knftpd: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2012-5905 being exploited?

CVE-2012-5905 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2012-5905 affect?

CVE-2012-5905 affects knftpd. Severity is medium (CVSS 4.0). Buffer overflow in KnFTPd 1.0.0 allows remote authenticated users to cause a denial of service (crash) via a long string in a FEAT command.

How urgent is CVE-2012-5905?

Priority 41/100. Public exploit reference

References

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