CVE-2019-15690
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 · uneditedLibVNCServer 0.9.12 release and earlier contains heap buffer overflow vulnerability within the HandleCursorShape() function in libvncclient/cursor.c. An attacker sends cursor shapes with specially crafted dimensions, which can result in remote code execution.
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 confidenceHeap buffer overflow vulnerability in LibVNCServer's HandleCursorShape() function in libvncclient/cursor.c. Attackers can send cursor shapes with specially crafted dimensions to trigger overflow and achieve remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Identify LibVNCServer installationRun 'dpkg -l | grep libvncserver' on Debian/Ubuntu, 'rpm -qa | grep libvncserver' on RHEL/CentOS, or check for libraries in '/usr/lib/' containing 'vncclient' in the filenameAffected if LibVNCServer libraries are present on the system
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Determine LibVNCServer versionCheck the library version: 'objdump -p /usr/lib/x86_64-linux-gnu/libvncclient.so | grep Version' or 'ldd' output, or check package manager for version infoAffected if The installed version is earlier than the patched release (post 0.9.12)
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Identify software using LibVNCServerSearch for applications that link against libvncclient: 'ldconfig -p | grep vncclient' or review installed VNC client packages (krdc, remmina, etc.)Affected if VNC client applications linked to a vulnerable libvncclient version are installed
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Check for active VNC client usageReview running processes for VNC client applications, or check configuration files in user home directories for VNC connection profiles (.vnc, .remmina)Affected if Users have VNC client configurations that could connect to remote VNC servers
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Inspect the cursor.c source file if availableLocate libvncclient source code in the system or build directories and verify the HandleCursorShape() function for the fix (look for bounds checking on cursor width/height parameters)Affected if The source code contains the vulnerable HandleCursorShape() function without proper bounds validation on cursor dimensions
The system is affected if it runs any VNC client software linked to an unpatched LibVNCServer version (earlier than post-0.9.12) that could connect to untrusted VNC servers.
Generated from the published advisory. Verify against your own configuration.
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 dataUpdate LibVNCServer to a patched version (post 0.9.12) or apply available vendor patches. If immediate patching is not feasible, restrict VNC service access to trusted networks to reduce attack surface.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-15690 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-15690 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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