X11r6Application · Xfree86 Project

CVE-2003-0063

HIGH · 7.3 CVSS v3.1 Published 2003-03-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The xterm terminal emulator in XFree86 4.2.0 and earlier allows attackers to modify the window title via a certain character escape sequence and then insert it back to the command line in the user's terminal, e.g. when the user views a file containing the malicious sequence, which could allow the attacker to execute arbitrary commands.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The xterm terminal emulator in XFree86 4.2.0 and earlier allows attackers to modify the window title via a specific character escape sequence (ESC]0;...BEL) and then inject it back to the command line when the user views a file containing the malicious sequence, potentially allowing arbitrary command execution through the shell.

MitigationUpdate to a patched version of xterm/XFree86 that sanitizes escape sequences, or migrate to a modern terminal emulator that properly handles and filters control sequences from untrusted input.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
X11r6Application
Affected:= 4.0= 4.0.1= 4.0.3= 4.1.0= 4.2.0= 4.2.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm xterm is installed
    Run 'which xterm' or 'dpkg -l | grep xterm' (Debian) / 'rpm -qa | grep xterm' (RHEL) to see if the xterm package is present on the system
    Affected if xterm is installed and the system is running XFree86 4.2.1 or earlier versions (4.0, 4.0.1, 4.0.3, 4.1.0, 4.2.0)
  2. Identify the XFree86 version
    Run 'XFree86 -version' or check '/var/log/XFree86.0.log' for the version string. On Debian-based systems, also check 'dpkg -l | grep xfree86'
    Affected if The installed XFree86 version is 4.2.1, 4.2.0, 4.1.0, 4.0.3, 4.0.1, or 4.0 (exact match versions)
  3. Verify xterm binary version
    Run 'xterm -version' to get the xterm version number, which typically correlates with the underlying XFree86 release
    Affected if The xterm version corresponds to XFree86 4.2.1 or earlier
  4. Check if window title escape sequences can be processed
    Create a test file containing the escape sequence (printf '\033]0;test\007\n') and use 'cat' or 'less' to display it in xterm, observing whether the window title changes
    Affected if The window title changes to 'test' after viewing the file, indicating the vulnerable escape sequence handling is active

If the system runs XFree86 versions 4.0 through 4.2.1 with xterm and displays untrusted content that could contain escape sequences, the environment is affected by this vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to a patched version of xterm/XFree86 that sanitizes escape sequences, or migrate to a modern terminal emulator that properly handles and filters control sequences from untrusted input.

Fix this in X11r6 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2003-0063 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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