dbcve.org
XzApplication · Tukaani

CVE-2024-3094

CRITICAL · 10.0 CVSS v3.1 Published 2024-03-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
High EPSS 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
Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0. Through a series of complex obfuscations, the liblzma build process extracts a prebuilt object file from a disguised test file existing in the source code, which is then used to modify specific functions in the liblzma code. This results in a modified liblzma library that can be used by any software linked against this library, intercepting and modifying the data interaction with this library.

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

A supply chain attack was discovered in xz-utils versions 5.6.0 and 5.6.1 where malicious code was inserted into upstream tarballs. The build process for liblzma extracts a prebuilt object file from a disguised test file, which modifies specific functions in the library to create a backdoor that intercepts and manipulates data interactions with liblzma.

MitigationImmediately downgrade xz-utils to version 5.4.x or earlier on all affected systems. Audit systems for signs of compromise and rebuild affected systems if necessary. Monitor for official safe releases of 5.6.x.

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
XzApplication
Affected:= 5.6.0= 5.6.1

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
Changed
Confidentiality
High
Integrity
High
Availability
High

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

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 xz-utils version
    Run 'xz --version' or 'xz -V' to display the installed version. Alternatively, use your system's package manager (dpkg -l xz-utils, rpm -q xz-utils, etc.) to query the installed package version.
    Affected if The version displayed is exactly 5.6.0 or 5.6.1
  2. Verify library presence
    Check if liblzma is present on the system by running 'ldconfig -p | grep liblzma' or looking for /usr/lib/liblzma.so* (path may vary by distribution).
    Affected if liblzma is present and the xz-utils version is 5.6.0 or 5.6.1
  3. Confirm runtime linkage
    Use 'ldd /usr/bin/xz' (or the full path to xz binary) to see which libraries the xz binary links against at runtime, specifically checking for liblzma.
    Affected if The binary links against liblzma and the xz version is 5.6.0 or 5.6.1

If xz-utils version 5.6.0 or 5.6.1 is installed and linked to liblzma, the environment is affected by this supply chain backdoor.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Immediately downgrade xz-utils to version 5.4.x or earlier on all affected systems. Audit systems for signs of compromise and rebuild affected systems if necessary. Monitor for official safe releases of 5.6.x.

Recommended fix High confidence

xz 5.6.2 or xz 5.4.x (stable unaffected version)

  1. 1. Identify systems with xz-utils installed by running: dpkg -l | grep xz or rpm -qa | grep xz
  2. 2. Check the installed version using: xz --version
  3. 3. If version is 5.6.0 or 5.6.1, immediately remove or downgrade the package
  4. 4. For Debian/Ubuntu systems: apt remove xz-utils && apt install xz-utils (will install a safe version)
  5. 5. For RHEL/CentOS systems: yum downgrade xz or dnf downgrade xz
  6. 6. Verify the version after remediation: xz --version
  7. 7. Ensure the version is either 5.4.x series or 5.6.2+
  8. 8. Monitor for any unusual behavior and check system integrity
Caveat Some legacy scripts may have compatibility issues with older xz versions; test in staging before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Xz Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA6.0 h
42.0 hours of engineering $7,360
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,776.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-3094 — 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-2024-3094 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