Half LifeApplication · Valve Software

CVE-2001-0964

HIGH · 7.5 CVSS v2.0 Published 2001-09-20
Fix available
A fix is available. Upgrade to after 1.1.0.8 or later.
See remediation →
84/100
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
Buffer overflow in client for Half-Life 1.1.0.8 and earlier allows malicious remote servers to execute arbitrary code via a long console command.

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

Buffer overflow vulnerability in the Half-Life game client (versions 1.1.0.8 and earlier) allows malicious remote game servers to execute arbitrary code on connected clients by sending specially crafted long console commands that overflow a buffer in the client software.

MitigationUpgrade the Half-Life client to a version newer than 1.1.0.8, or if the software is obsolete and no longer supported, discontinue use and migrate to modern game clients.

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
Half LifeApplication
Affected:<= 1.1.0.8

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
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

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. Check if Half-Life client is installed
    Look for the Half-Life installation directory (commonly C:\Program Files\Half-Life or C:\Program Files (x86)\Half-Life on Windows, or ~/.half-life/ on Linux) and verify the presence of hl.exe or the half-life executable
    Affected if Half-Life client software is found on the system
  2. Determine the installed Half-Life version
    Right-click on hl.exe, select Properties, and check the File Version field in the Details tab. Alternatively, launch the game and type 'version' in the console (press ~ to open console) to display the client version
    Affected if The displayed version number is 1.1.0.8 or earlier (such as 1.1.0.7, 1.1.0.6, etc.)
  3. Verify the version matches affected range
    Compare your installed version against the affected range: any version less than or equal to 1.1.0.8 is vulnerable. Version 1.1.1.0 or higher is not affected
    Affected if The installed version is 1.1.0.8 or any earlier version number
  4. Confirm client usage exposure
    Check if the Half-Life client is configured to automatically connect to servers or if it has been used recently to join multiplayer games, as the vulnerability is triggered when connecting to a remote game server sending malicious console commands
    Affected if The client has been used to connect to untrusted or unknown game servers, or auto-connect settings are enabled

If Half-Life client version 1.1.0.8 or earlier is installed and has been used to connect to remote game servers, the system is affected by this buffer overflow 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
Upgrade available Upgrade to a release after 1.1.0.8
Interim mitigation

Upgrade the Half-Life client to a version newer than 1.1.0.8, or if the software is obsolete and no longer supported, discontinue use and migrate to modern game clients.

Fix this in Half Life Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2001-0964 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2001-0964 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data