CVE-2003-1143: Croteam Serious Sam demo test 2 2.1a, Serious Sam: the First Encounter 1.05, and Serious Sam: the Second Encou

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HIGH 7.5DOWNGRADE

CVE-2003-1143 is a high-severity flaw (CVSS 7.5) affecting serioussam. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Croteam Serious Sam demo test 2 2.1a, Serious Sam: the First Encounter 1.05, and Serious Sam: the Second Encounter 1.05 allow remote attackers to cause a denial of service (crash or freeze) via a TCP packet with an invalid first parameter.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	2.8% (top 14%)
CISA exploited list	No
Published	2003-10-30
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: croteam

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

Am I affected?

Timeline

2003-10-30 05:00 UTCPublished CVE record published
2026-06-16 22:03 UTCUpdated Record last modified

croteam serioussam DOWNGRADE

Affected: test_2_2.1_a · the_first_encounter_1.0.5 · the_second_encounter_1.0.5 · the_second_encounter_demo

Fixed in: no fixed release known

Safe to downgrade to: a release before test_2_2.1_a

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before test_2_2.1_a (Debian / Ubuntu)

apt-cache madison serioussam sudo apt install serioussam=<VERSION_BEFORE_test_2_2.1_a> sudo apt-mark hold serioussam

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

dnf --showduplicates list serioussam sudo dnf downgrade serioussam-<VERSION_BEFORE_test_2_2.1_a> sudo dnf versionlock add serioussam

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: Serious Sam Engine 1.0.5 - Remote Denial of Service

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-2003-1143?

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

Is CVE-2003-1143 being exploited?

CVE-2003-1143 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-2003-1143 affect?

CVE-2003-1143 affects serioussam. Severity is high (CVSS 7.5). Croteam Serious Sam demo test 2 2.1a, Serious Sam: the First Encounter 1.05, and Serious Sam: the Second Encounter 1.05 allow remote attackers to cause a denial of service (crash or freeze) via a TCP packet with an invalid first parameter.

How urgent is CVE-2003-1143?

Priority 53/100. High severity; Public exploit reference

References

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