CVE-2003-1188: Unichat allows remote attackers to cause a denial of service (crash) by adding extra chat characters (avatars)

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MEDIUM 5.0DOWNGRADE

CVE-2003-1188 is a medium-severity flaw (CVSS 5.0) affecting unichat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Unichat allows remote attackers to cause a denial of service (crash) by adding extra chat characters (avatars) and logging in to a chat room, as demonstrated using duplicate ACTOR entries in u2res000.rit.

Why this priority

Public exploit reference

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	2003-11-02
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: unichat

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

Am I affected?

Timeline

2003-11-02 05:00 UTCPublished CVE record published
2026-06-16 22:03 UTCUpdated Record last modified

unichat unichat DOWNGRADE

Affected: 2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

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

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

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

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

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

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-2003-1188?

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

Is CVE-2003-1188 being exploited?

CVE-2003-1188 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-2003-1188 affect?

CVE-2003-1188 affects unichat. Severity is medium (CVSS 5.0). Unichat allows remote attackers to cause a denial of service (crash) by adding extra chat characters (avatars) and logging in to a chat room, as demonstrated using duplicate ACTOR entries in u2res000.rit.

How urgent is CVE-2003-1188?

Priority 42/100. Public exploit reference

References

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