TwikiApplication

CVE-2008-4998

MEDIUM · 6.9 CVSS v2.0 Published 2008-11-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
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
postinst in twiki 4.1.2 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/twiki temporary file. NOTE: the vendor disputes this vulnerability, stating "this bug is invalid.

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 · moderate confidence

The postinst installation script for TWiki 4.1.2 creates a temporary file at /tmp/twiki without checking for existing symlinks or using safe temporary file creation methods. A local attacker can pre-create a symlink at this location pointing to an arbitrary target file, causing the postinst script to overwrite that file when it executes.

MitigationReplace insecure temporary file creation with mktemp or equivalent safe methods, add symlink detection checks before file creation, and ensure proper file permissions on temporary directories.

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
TwikiApplication
Affected:= 4.1.2

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
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/AC:M/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. Confirm TWiki installation exists
    Look for TWiki installation directories such as /twiki, /var/www/twiki, or /opt/twiki. Check for twiki bin and lib paths.
    Affected if No TWiki installation is found, this CVE does not apply.
  2. Identify installed TWiki version
    Check the TWiki version file (often TWiki.pm in lib/TWiki.pm or a VERSION file in the installation root). Compare the version to 4.1.2.
    Affected if The installed version is not 4.1.2, this specific CVE does not apply.
  3. Locate and examine postinst script
    Look for postinst or preinst scripts in the TWiki installation (often in /twiki/installer or the original package). Search for references to /tmp/twiki in these scripts.
    Affected if The postinst script contains unsymlink-checked creation of /tmp/twiki, indicating the vulnerability is present.
  4. Check for residual /tmp/twiki symlink
    Run 'ls -la /tmp/twiki' to see if a symlink exists at that location.
    Affected if A symlink at /tmp/twiki pointing to an unintended target exists, suggesting possible exploitation occurred.

You are affected if TWiki version 4.1.2 was installed and the postinst script creates /tmp/twiki without symlink checks.

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

Replace insecure temporary file creation with mktemp or equivalent safe methods, add symlink detection checks before file creation, and ensure proper file permissions on temporary directories.

Fix this in Twiki Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,780
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2008-4998 — 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-2008-4998 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