CVE-2009-4593: The bftpdutmp_log function in bftpdutmp.c in Bftpd before 2.4 does not place a '\0' character at the end of th

Q: How do I fix CVE-2009-4593?

bftpd: upgrade to newer than 2.3. Exact commands for each OS are on this page.

Q: Is CVE-2009-4593 being exploited?

CVE-2009-4593 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-2009-4593 affect?

CVE-2009-4593 affects bftpd. Severity is medium (CVSS 5.0). The bftpdutmp_log function in bftpdutmp.c in Bftpd before 2.4 does not place a '\0' character at the end of the string value of the ut.bu_host structure member, which might allow remote attackers to cause a denial of service (daemon crash)

Q: How urgent is CVE-2009-4593?

Priority 36/100. No elevated risk signals yet.

Routine

MEDIUM 5.0UPGRADE

CVE-2009-4593 is a medium-severity flaw (CVSS 5.0) affecting bftpd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The bftpdutmp_log function in bftpdutmp.c in Bftpd before 2.4 does not place a '\0' character at the end of the string value of the ut.bu_host structure member, which might allow remote attackers to cause a denial of service (daemon crash) via unspecified vectors. NOTE: some of these details are obtained from third party information.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.4% (top 27%)
CISA exploited list	No
Published	2010-01-07
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: jesse smith

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

Am I affected?

Timeline

2010-01-07 18:30 UTCPublished CVE record published
2026-06-16 23:13 UTCUpdated Record last modified

jesse smith bftpd UPGRADE

Affected: <= 2.3 · 1.6 · 1.7 · 1.7.2 · 1.8 · 2.0.2 · 2.0.3 · 2.1

Fixed in: newer than 2.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bftpd

Note

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

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-2009-4593?

bftpd: upgrade to newer than 2.3. Exact commands for each OS are on this page.

Is CVE-2009-4593 being exploited?

CVE-2009-4593 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-2009-4593 affect?

CVE-2009-4593 affects bftpd. Severity is medium (CVSS 5.0). The bftpdutmp_log function in bftpdutmp.c in Bftpd before 2.4 does not place a '\0' character at the end of the string value of the ut.bu_host structure member, which might allow remote attackers to cause a denial of service (daemon crash)

How urgent is CVE-2009-4593?

Priority 36/100. No elevated risk signals yet.

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References

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