CVE-2006-6564: FileZilla Server before 0.9.22 allows remote attackers to cause a denial of service (crash) via a malformed ar

Q: How do I fix CVE-2006-6564?

filezilla: upgrade to newer than 0.9.21. Exact commands for each OS are on this page.

Q: Is CVE-2006-6564 being exploited?

CVE-2006-6564 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2006-6564 affect?

CVE-2006-6564 affects filezilla. Severity is medium (CVSS 4.0). FileZilla Server before 0.9.22 allows remote attackers to cause a denial of service (crash) via a malformed argument to the STOR command, which results in a NULL pointer dereference. NOTE: CVE analysis suggests that the problem might be du

Q: How urgent is CVE-2006-6564?

Priority 42/100. EPSS top 7%: very likely to be exploited; Public exploit reference

This month

MEDIUM 4.0UPGRADE

CVE-2006-6564 is a medium-severity flaw (CVSS 4.0) affecting filezilla. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FileZilla Server before 0.9.22 allows remote attackers to cause a denial of service (crash) via a malformed argument to the STOR command, which results in a NULL pointer dereference. NOTE: CVE analysis suggests that the problem might be due to a malformed PORT command.

Why this priority

EPSS top 7%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.0 (Medium)
EPSS exploit chance	6.1% (top 7%)
CISA exploited list	No
Published	2006-12-15
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: filezilla

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

Am I affected?

Timeline

2006-12-15 11:28 UTCPublished CVE record published
2026-06-16 22:33 UTCUpdated Record last modified

filezilla filezilla UPGRADE

Affected: <= 0.9.21

Fixed in: newer than 0.9.21

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 0.9.21 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade filezilla

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade filezilla

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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: FileZilla FTP Server 0.9.20b/0.9.21 - 'STOR' Denial of Service
Exploit-DB: FileZilla FTP Server 0.9.21 - 'LIST/NLST' Denial of Service

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-2006-6564?

filezilla: upgrade to newer than 0.9.21. Exact commands for each OS are on this page.

Is CVE-2006-6564 being exploited?

CVE-2006-6564 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-2006-6564 affect?

CVE-2006-6564 affects filezilla. Severity is medium (CVSS 4.0). FileZilla Server before 0.9.22 allows remote attackers to cause a denial of service (crash) via a malformed argument to the STOR command, which results in a NULL pointer dereference. NOTE: CVE analysis suggests that the problem might be du

How urgent is CVE-2006-6564?

Priority 42/100. EPSS top 7%: very likely to be exploited; Public exploit reference

Software pages

FileZilla vulnerabilities

Related CVEs

CVE-2007-2318 HIGH 9.3 UPGRADE Multiple format string vulnerabilities in FileZilla before 2.2.32 allow remote attackers to execute arbitrary
CVE-2007-0317 HIGH 7.5 UPGRADE Format string vulnerability in the LogMessage function in FileZilla before 3.0.0-beta5 allows remote attackers
CVE-2007-0315 HIGH 9.3 UPGRADE Multiple buffer overflows in FileZilla before 2.2.30a allow remote attackers to execute arbitrary code or caus
CVE-2006-2403 HIGH 7.5 DOWNGRADE Buffer overflow in FileZilla before 2.2.23 allows remote attackers to execute arbitrary commands via unknown a
CVE-2005-2898 MEDIUM 4.6 DOWNGRADE NOTE: this issue has been disputed by the vendor

References

← Back to latest CVEs