dbcve.org
XenApplication

CVE-2008-4993

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
qemu-dm.debug in Xen 3.2.1 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/args 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 · moderate confidence

The qemu-dm.debug component in Xen 3.2.1 creates a temporary file at /tmp/args without proper safety checks. A local attacker can create a symlink at this location before the debug binary runs, causing it to write to an arbitrary file specified by the attacker, leading to privilege escalation or denial of service.

MitigationRemove or disable the qemu-dm.debug binary, or upgrade to a patched version of Xen. Ensure proper /tmp directory restrictions and monitor for symlink-based attacks.

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
XenApplication
Affected:= 3.2.1

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
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. Identify installed Xen version
    Run 'xm info' or 'xl info' and look for the hypervisor version, or check the installed package version using your package manager (e.g., 'rpm -q xen' or 'dpkg -l xen')
    Affected if The installed Xen version is 3.2.1
  2. Locate qemu-dm.debug binary
    Search for the qemu-dm.debug file using 'find / -name qemu-dm.debug 2>/dev/null' or check common Xen binary directories such as /usr/lib/xen/bin/ or /usr/lib64/xen/bin/
    Affected if The qemu-dm.debug binary exists on the system
  3. Check /tmp/args file or symlink
    Run 'ls -la /tmp/args' to inspect whether this file or symlink currently exists
    Affected if A symlink at /tmp/args exists pointing to a sensitive target, or the file is writable by untrusted users
  4. Verify qemu-dm.debug permissions
    Run 'ls -la <path-to-qemu-dm.debug>' to check if the binary is executable and who owns it
    Affected if The binary is executable and owned by a privileged user (root), making symlink exploitation impactful

The system is affected if running Xen 3.2.1 with the qemu-dm.debug binary present and the /tmp/args file is accessible for symlink manipulation.

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

Remove or disable the qemu-dm.debug binary, or upgrade to a patched version of Xen. Ensure proper /tmp directory restrictions and monitor for symlink-based attacks.

Fix this in Xen 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 help mitigating

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-2008-4993 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2008-4993 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