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LibreofficeApplication

CVE-2018-14939

CRITICAL · 9.8 CVSS v3.0 Published 2018-08-05
Fix available
A fix is available. Upgrade to after 6.0.5 or later.
See remediation →
100/100
Remediation priority · Urgent
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
The get_app_path function in desktop/unx/source/start.c in LibreOffice through 6.0.5 mishandles the realpath function in certain environments such as FreeBSD libc, which might allow attackers to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact if LibreOffice is automatically launched during web browsing with pathnames controlled by a remote web site.

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 buffer overflow vulnerability exists in the get_app_path function in desktop/unx/source/start.c of LibreOffice through 6.0.5. The function mishandles the realpath function in certain environments such as FreeBSD libc, leading to a buffer overflow when processing pathnames. This can be triggered when LibreOffice is automatically launched during web browsing with attacker-controlled pathnames, potentially allowing denial of service or further exploitation.

MitigationUpgrade LibreOffice to version 6.0.6 or later which contains the fix for proper realpath buffer handling. As a defensive measure, avoid automatically launching LibreOffice from untrusted web content or hyperlinks.

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
LibreofficeApplication
Affected:<= 6.0.5

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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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 installed LibreOffice version
    Run ' libreoffice --version ' or ' soffice --version ' from command line, or check the application's About dialog. Compare the version number to the affected range (<= 6.0.5).
    Affected if The installed version is 6.0.5 or earlier.
  2. Identify the operating system libc implementation
    Check if the system is running FreeBSD or a derivative. Run ' uname -a ' and review the output, or check the libc version with ' ldd --version ' on Linux versus ' /usr/lib/libc.so.* ' on FreeBSD.
    Affected if The system uses FreeBSD libc which is mentioned as the specific environment where realpath mishandling occurs.
  3. Verify if LibreOffice can be launched via URL schemes
    Check browser and system settings for applications registered to handle LibreOffice URL schemes (such as 'libreoffice:' or 'loffice:'). Review browser plugin/extension settings and system file associations.
    Affected if LibreOffice is registered to handle URL schemes that could be triggered from web content, allowing attacker-controlled pathnames to reach the vulnerable get_app_path function.
  4. Review the vulnerable source file presence
    If source code inspection is possible, verify the presence of desktop/unx/source/start.c and examine the get_app_path function for realpath buffer handling without proper size limits.
    Affected if The vulnerable code path exists in the installed binary and realpath is called without adequate buffer size checking.

A user is affected if LibreOffice version 6.0.5 or earlier is installed, particularly on FreeBSD systems where the realpath buffer overflow can be triggered via attacker-controlled pathnames from web content.

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
Upgrade available Upgrade to a release after 6.0.5
Interim mitigation

Upgrade LibreOffice to version 6.0.6 or later which contains the fix for proper realpath buffer handling. As a defensive measure, avoid automatically launching LibreOffice from untrusted web content or hyperlinks.

Recommended fix Moderate confidence

LibreOffice 6.0.6 or later stable release

  1. Update your system's package repository to ensure you have the latest package information
  2. Install the latest LibreOffice version available in your distribution's repositories (version 6.0.6 or later)
  3. On Debian/Ubuntu-based systems: sudo apt-get update && sudo apt-get install libreoffice
  4. On Red Hat/Fedora-based systems: sudo dnf update libreoffice
  5. On SUSE-based systems: sudo zypper update libreoffice
  6. After updating, verify the installed version using: libreoffice --version
Caveat Minimal risk - point releases typically contain only bug fixes and security patches without breaking API or feature changes

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

Fix this in Libreoffice Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA6.0 h
34.0 hours of engineering $5,940
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,504.

Scan for this in your stack

Free · runs locally
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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-2018-14939 in production — separate from our analysis above.

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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