CVE-2000-0504: libICE in XFree86 allows remote attackers to cause a denial of service by specifying a large value which is no

This month

MEDIUM 5.0DOWNGRADEDOWNGRADEDOWNGRADE

CVE-2000-0504 is a medium-severity flaw (CVSS 5.0) affecting gdm, x, x11r6. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

libICE in XFree86 allows remote attackers to cause a denial of service by specifying a large value which is not properly checked by the SKIP_STRING macro.

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	3.3% (top 12%)
CISA exploited list	No
Published	2000-06-19
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: gnome · open group · xfree86 project

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

Am I affected?

Timeline

2000-06-19 04:00 UTCPublished CVE record published
2026-06-16 21:51 UTCUpdated Record last modified

gnome gdm DOWNGRADE

Affected: 1.0 · 1.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison gdm sudo apt install gdm=<VERSION_BEFORE_1.0> sudo apt-mark hold gdm

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

dnf --showduplicates list gdm sudo dnf downgrade gdm-<VERSION_BEFORE_1.0> sudo dnf versionlock add gdm

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.

open group x DOWNGRADE

Affected: 11.0r5 · 11.0r6 · 11.0r6.1 · 11.0r6.2 · 11.0r6.3 · 11.0r6.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.0r5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 11.0r5 (Debian / Ubuntu)

apt-cache madison x sudo apt install x=<VERSION_BEFORE_11.0r5> sudo apt-mark hold x

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

dnf --showduplicates list x sudo dnf downgrade x-<VERSION_BEFORE_11.0r5> sudo dnf versionlock add x

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.

xfree86 project x11r6 DOWNGRADE

Affected: 3.3.3 · 3.3.4 · 3.3.5 · 3.3.6 · 4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.3.3

1. Check installed version

apt-cache policy x11r6 || rpm -q x11r6 || x11r6 --version

2. No fixed release: DOWNGRADE to a release before 3.3.3 (Debian / Ubuntu)

apt-cache madison x11r6 sudo apt install x11r6=<VERSION_BEFORE_3.3.3> sudo apt-mark hold x11r6

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

dnf --showduplicates list x11r6 sudo dnf downgrade x11r6-<VERSION_BEFORE_3.3.3> sudo dnf versionlock add x11r6

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: Gnome 1.0/1.1 / Group X 11.0 / XFree86 X11R6 3.3.x/4.0 - 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-2000-0504?

gdm: downgrade or apply the listed mitigation; x: downgrade or apply the listed mitigation; x11r6: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2000-0504 being exploited?

CVE-2000-0504 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-2000-0504 affect?

CVE-2000-0504 affects gdm, x, x11r6. Severity is medium (CVSS 5.0). libICE in XFree86 allows remote attackers to cause a denial of service by specifying a large value which is not properly checked by the SKIP_STRING macro.

How urgent is CVE-2000-0504?

Priority 45/100. Public exploit reference

Related CVEs

CVE-2011-1709 HIGH 7.2 DOWNGRADE GNOME Display Manager (gdm) before 2.32.2, when glib 2.28 is used, enables execution of a web browser with the
CVE-2011-0727 MEDIUM 6.9 DOWNGRADE GNOME Display Manager (gdm) 2.x before 2.32.1 allows local users to change the ownership of arbitrary files vi
CVE-2009-2697 MEDIUM 6.8 UPGRADE The Red Hat build script for the GNOME Display Manager (GDM) before 2.16.0-56 on Red Hat Enterprise Linux (RHE
CVE-2007-3381 LOW 1.5 UPGRADE The GDM daemon in GNOME Display Manager (GDM) before 2.14.13, 2.16.x before 2.16.7, 2.18.x before 2.18.4, and
CVE-2006-6105 MEDIUM 4.3 DOWNGRADE Format string vulnerability in the host chooser window (gdmchooser) in GNOME Foundation Display Manager (gdm)

References

← Back to latest CVEs