CVE-2004-0393: Format string vulnerability in the msg function for rlpr daemon (rlprd) 2.0.4 allows remote attackers to execu

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HIGH 10.0DOWNGRADE

CVE-2004-0393 is a high-severity flaw (CVSS 10.0) affecting rlpr. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Format string vulnerability in the msg function for rlpr daemon (rlprd) 2.0.4 allows remote attackers to execute arbitrary code via format string specifiers in a buffer that can not be resolved, which is provided to the syslog function.

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	17.4% (top 3%)
CISA exploited list	No
Published	2004-12-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: rlpr

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

Am I affected?

Timeline

2004-12-06 05:00 UTCPublished CVE record published
2026-06-16 22:05 UTCUpdated Record last modified

rlpr rlpr DOWNGRADE

Affected: 2.0 · 2.0.1 · 2.0.2 · 2.0.3 · 2.0.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison rlpr sudo apt install rlpr=<VERSION_BEFORE_2.0> sudo apt-mark hold rlpr

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

dnf --showduplicates list rlpr sudo dnf downgrade rlpr-<VERSION_BEFORE_2.0> sudo dnf versionlock add rlpr

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: Rlpr 2.0 - 'msg()' Multiple Vulnerabilities
Exploit-DB: Rlpr 2.04 - 'msg()' Remote Format String

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-2004-0393?

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

Is CVE-2004-0393 being exploited?

CVE-2004-0393 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-2004-0393 affect?

CVE-2004-0393 affects rlpr. Severity is high (CVSS 10.0). Format string vulnerability in the msg function for rlpr daemon (rlprd) 2.0.4 allows remote attackers to execute arbitrary code via format string specifiers in a buffer that can not be resolved, which is provided to the syslog function.

How urgent is CVE-2004-0393?

Priority 64/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2004-0454 HIGH 7.2 DOWNGRADE Buffer overflow in the msg function for rlpr daemon (rlprd) 2.04 allows local users to execute arbitrary code.

References

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