CVE-2000-0583: vchkpw program in vpopmail before version 4.8 does not properly cleanse an untrusted format string used in a c

Routine

MEDIUM 5.0DOWNGRADE

CVE-2000-0583 is a medium-severity flaw (CVSS 5.0) affecting vpopmail vchkpw. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

vchkpw program in vpopmail before version 4.8 does not properly cleanse an untrusted format string used in a call to syslog, which allows remote attackers to cause a denial of service via a USER or PASS command that contains arbitrary formatting directives.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Published	2000-06-30
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: inter7

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

Am I affected?

Timeline

2000-06-30 04:00 UTCPublished CVE record published
2026-06-16 21:52 UTCUpdated Record last modified

inter7 vpopmail vchkpw DOWNGRADE

Affected: 4.5 · 4.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.5

1. Check installed version

apt-cache policy vpopmail-vchkpw || rpm -q vpopmail-vchkpw || vpopmail-vchkpw --version

2. No fixed release: DOWNGRADE to a release before 4.5 (Debian / Ubuntu)

apt-cache madison vpopmail-vchkpw sudo apt install vpopmail-vchkpw=<VERSION_BEFORE_4.5> sudo apt-mark hold vpopmail-vchkpw

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

dnf --showduplicates list vpopmail-vchkpw sudo dnf downgrade vpopmail-vchkpw-<VERSION_BEFORE_4.5> sudo dnf versionlock add vpopmail-vchkpw

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.

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-2000-0583?

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

Is CVE-2000-0583 being exploited?

CVE-2000-0583 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-2000-0583 affect?

CVE-2000-0583 affects vpopmail vchkpw. Severity is medium (CVSS 5.0). vchkpw program in vpopmail before version 4.8 does not properly cleanse an untrusted format string used in a call to syslog, which allows remote attackers to cause a denial of service via a USER or PASS command that contains arbitrary forma

How urgent is CVE-2000-0583?

Priority 37/100. No elevated risk signals yet.

References

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