CVE-2001-0550: wu-ftpd 2.6.1 allows remote attackers to execute arbitrary commands via a "~{" argument to commands such as CW

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HIGH 7.5DOWNGRADEDOWNGRADE

CVE-2001-0550 is a high-severity flaw (CVSS 7.5) affecting ftpd-bsd, wu-ftpd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

wu-ftpd 2.6.1 allows remote attackers to execute arbitrary commands via a "~{" argument to commands such as CWD, which is not properly handled by the glob function (ftpglob).

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	74.1% (top 1%)
CISA exploited list	No
Published	2001-11-30
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: david madore · washington university

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

Am I affected?

Timeline

2001-11-30 05:00 UTCPublished CVE record published
2026-06-16 21:54 UTCUpdated Record last modified

david madore ftpd-bsd DOWNGRADE

Affected: 0.3.2 · 0.3.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.3.2

1. Check installed version

apt-cache policy ftpd-bsd || rpm -q ftpd-bsd || ftpd-bsd --version

2. No fixed release: DOWNGRADE to a release before 0.3.2 (Debian / Ubuntu)

apt-cache madison ftpd-bsd sudo apt install ftpd-bsd=<VERSION_BEFORE_0.3.2> sudo apt-mark hold ftpd-bsd

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

dnf --showduplicates list ftpd-bsd sudo dnf downgrade ftpd-bsd-<VERSION_BEFORE_0.3.2> sudo dnf versionlock add ftpd-bsd

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.

washington university wu-ftpd DOWNGRADE

Affected: 2.5.0 · 2.6.0 · 2.6.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.5.0

1. Check installed version

apt-cache policy wu-ftpd || rpm -q wu-ftpd || wu-ftpd --version

2. No fixed release: DOWNGRADE to a release before 2.5.0 (Debian / Ubuntu)

apt-cache madison wu-ftpd sudo apt install wu-ftpd=<VERSION_BEFORE_2.5.0> sudo apt-mark hold wu-ftpd

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

dnf --showduplicates list wu-ftpd sudo dnf downgrade wu-ftpd-<VERSION_BEFORE_2.5.0> sudo dnf versionlock add wu-ftpd

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: WU-FTPD 2.6.1 - Remote Command Execution
Exploit-DB: WU-FTPD 2.6 - File Globbing Heap Corruption

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-2001-0550?

ftpd-bsd: downgrade or apply the listed mitigation; wu-ftpd: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2001-0550 being exploited?

CVE-2001-0550 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-2001-0550 affect?

CVE-2001-0550 affects ftpd-bsd, wu-ftpd. Severity is high (CVSS 7.5). wu-ftpd 2.6.1 allows remote attackers to execute arbitrary commands via a "~{" argument to commands such as CWD, which is not properly handled by the glob function (ftpglob).

How urgent is CVE-2001-0550?

Priority 56/100. High severity; EPSS top 1%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2001-0053 HIGH 10.0 DOWNGRADE MITIGATE One-byte buffer overflow in replydirname function in BSD-based ftpd allows remote attackers to gain root privi

References

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