RealvncApplication

CVE-2013-6886

HIGH · 7.2 CVSS v2.0 Published 2013-12-28
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
RealVNC VNC 5.0.6 on Mac OS X, Linux, and UNIX allows local users to gain privileges via a crafted argument to the (1) vncserver, (2) vncserver-x11, or (3) Xvnc helper.

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

RealVNC VNC 5.0.6 contains a local privilege escalation vulnerability where local users can gain elevated system privileges by supplying crafted arguments to the vncserver, vncserver-x11, or Xvnc helper programs on Mac OS X, Linux, and UNIX platforms.

MitigationUpgrade to a patched version of RealVNC VNC or apply vendor security updates. If immediate patching is not feasible, restrict execution permissions on the affected helper binaries or remove them if unnecessary.

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
RealvncApplication
Affected:= 5.0.6

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. Confirm RealVNC VNC installation
    Run 'dpkg -l | grep -i vnc' on Debian-based systems, 'rpm -qa | grep -i vnc' on RHEL-based systems, or check for /usr/bin/vncserver, /usr/local/bin/vncserver, or similar vnc binaries.
    Affected if RealVNC software is installed on the system
  2. Identify installed RealVNC version
    Run 'vncserver -version' or 'vncserver-x11 -version', or check the package version using the system package manager (dpkg/rpm).
    Affected if The installed version is exactly 5.0.6
  3. Locate vulnerable helper binaries
    Search for the vncserver, vncserver-x11, and Xvnc binaries: 'which vncserver', 'which vncserver-x11', 'which Xvnc', or check common paths like /usr/bin/vnc*, /usr/local/bin/vnc*, /opt/VNC/bin/*.
    Affected if Any of these three helper programs (vncserver, vncserver-x11, or Xvnc) are present on the system
  4. Check permissions on helper binaries
    Run 'ls -la' on the identified helper binaries to view ownership and permissions. Look for setuid bit or group/world write permissions.
    Affected if The helper binaries have setuid bit set or overly permissive write permissions that could enable privilege escalation

A system is affected if RealVNC VNC version 5.0.6 is installed with the vulnerable helper programs (vncserver, vncserver-x11, or Xvnc) present and executable.

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

Upgrade to a patched version of RealVNC VNC or apply vendor security updates. If immediate patching is not feasible, restrict execution permissions on the affected helper binaries or remove them if unnecessary.

Fix this in Realvnc 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
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2013-6886 — 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-2013-6886 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