CVE-2003-1377: Buffer overflow in the reverse DNS lookup of Smart IRC Daemon (SIRCD) 0.4.0 and 0.4.4 allows remote attackers

This month

HIGH 8.3DOWNGRADE

CVE-2003-1377 is a high-severity flaw (CVSS 8.3) affecting sircd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the reverse DNS lookup of Smart IRC Daemon (SIRCD) 0.4.0 and 0.4.4 allows remote attackers to execute arbitrary code via a client with a long hostname.

Why this priority

High severity

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

Risk facts

CVSS score	8.3 (High)
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Weakness	CWE-119
Published	2003-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: sircd

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

Am I affected?

Timeline

2003-12-31 05:00 UTCPublished CVE record published
2026-06-16 22:04 UTCUpdated Record last modified

sircd sircd DOWNGRADE

Affected: 0.4.0 · 0.4.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.4.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.4.0 (Debian / Ubuntu)

apt-cache madison sircd sudo apt install sircd=<VERSION_BEFORE_0.4.0> sudo apt-mark hold sircd

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

dnf --showduplicates list sircd sudo dnf downgrade sircd-<VERSION_BEFORE_0.4.0> sudo dnf versionlock add sircd

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-2003-1377?

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

Is CVE-2003-1377 being exploited?

CVE-2003-1377 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-2003-1377 affect?

CVE-2003-1377 affects sircd. Severity is high (CVSS 8.3). Buffer overflow in the reverse DNS lookup of Smart IRC Daemon (SIRCD) 0.4.0 and 0.4.4 allows remote attackers to execute arbitrary code via a client with a long hostname.

How urgent is CVE-2003-1377?

Priority 51/100. High severity

References

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