ThttpdWeb server / proxy · Acme Labs

CVE-2006-4248

HIGH · 7.2 CVSS v2.0 Published 2006-10-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
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
thttpd on Debian GNU/Linux, and possibly other distributions, allows local users to create or touch arbitrary files via a symlink attack on the start_thttpd temporary file.

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

thttpd contains a symlink vulnerability in its temporary file handling for the start_thttpd file. When creating or touching this temporary file, thttpd does not verify the file is not a symlink, allowing local unprivileged users to create or modify arbitrary files on the system by pre-positioning a symlink at the expected temporary file location.

MitigationEnsure thttpd is not run as root and use safe temporary file creation methods (mkstemp with O_EXCL). Apply Debian security updates for this package. Restrict permissions on /var/tmp and similar directories to prevent pre-positioning of symlinks.

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
ThttpdWeb server / proxy
Affected:= 2.25b

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
Local
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

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

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. Identify thttpd installation and version
    Run 'thttpd -v' or 'dpkg -l | grep thttpd' or 'rpm -qa | grep thttpd' to determine if thttpd is installed and its version number
    Affected if The installed version is 2.25b
  2. Check thttpd process user
    Run 'ps aux | grep thttpd' to see what user the thttpd process runs as, or inspect the thttpd configuration file for a 'user' or 'www-data' directive
    Affected if thttpd runs as the root user rather than an unprivileged user
  3. Locate the temporary file directory
    Examine the thttpd configuration or init script for references to 'start_thttpd' temporary file path, commonly created in /var/tmp or /tmp
    Affected if thttpd creates a temporary file named 'start_thttpd' in a world-writable directory
  4. Inspect for existing symlinks at temp file location
    Check if a file or symlink already exists at the expected temporary file path (e.g., ls -la /var/tmp/start_thttpd)
    Affected if A symlink exists at the temporary file location pointing to a target file owned by root or another privileged location

A system is affected if it runs Acme Labs Thttpd version 2.25b and creates the start_thttpd temporary file in a directory with weak permissions where unprivileged users can pre-position symlinks.

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

Ensure thttpd is not run as root and use safe temporary file creation methods (mkstemp with O_EXCL). Apply Debian security updates for this package. Restrict permissions on /var/tmp and similar directories to prevent pre-positioning of symlinks.

Fix this in Thttpd Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2006-4248 — 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-2006-4248 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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