CVE-2016-5720
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 · uneditedMultiple untrusted search path vulnerabilities in Microsoft Skype allow local users to execute arbitrary code and conduct DLL hijacking attacks via a Trojan horse (1) msi.dll, (2) dpapi.dll, or (3) cryptui.dll that is located in the current working directory.
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 confidenceMicrosoft Skype contains multiple untrusted search path vulnerabilities allowing local privilege escalation and arbitrary code execution via DLL hijacking. The application loads DLLs (msi.dll, dpapi.dll, cryptui.dll) from the current working directory without proper path validation, enabling attackers to place malicious DLLs that Skype will load during execution.
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 dataall versionsCVSS 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
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify Skype installationSearch for Skype executable in typical installation paths: %ProgramFiles%\Microsoft\Skype\, %ProgramFiles(x86)%\Microsoft\Skype\, or %LocalAppData%\Microsoft\Skype\. Also check Start Menu shortcuts and PATH for skype.exe.Affected if Skype executable is found on the system.
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Check Skype executable versionRight-click skype.exe, select Properties, then view the Details tab to see File Version and Product Version. Alternatively, run 'wmic product where "name like '%skype%'" get version,name' or check Add/Remove Programs.Affected if Any version of Microsoft Skype is installed (all versions are affected per CVE).
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Identify user-writable directories where Skype could be launchedReview folder permissions on common user directories (Desktop, Downloads, Documents) to determine if standard users can create files. Use 'icacls <directory>' to check write permissions for the user context that would run Skype.Affected if Users have write permissions to directories from which they commonly launch Skype, allowing placement of malicious DLLs.
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Check for vulnerable DLL locationsSearch for msi.dll, dpapi.dll, and cryptui.dll in user-writable directories, particularly in locations where Skype shortcuts point to or where users commonly run Skype from. Use 'dir /s /b C:\Users\*\msi.dll 2>nul' to find copies in user directories.Affected if Any of the three vulnerable DLLs (msi.dll, dpapi.dll, cryptui.dll) exist in user-writable locations alongside or within directories used to launch Skype.
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Verify current working directory DLL loading behaviorLaunch Skype from a test user-writable directory (like a test folder on Desktop) and use Process Monitor (procmon) from Sysinternals to capture DLL load events. Filter for Skype.exe and look for DLL load attempts from the current working directory path.Affected if Skype attempts to load msi.dll, dpapi.dll, or cryptui.dll from the current working directory rather than only from secure system paths.
If Microsoft Skype is installed and users can launch it from directories where they have write permissions, the environment is vulnerable to DLL hijacking exploitation via CVE-2016-5720.
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 dataDeploy the vendor patch from Microsoft for Skype. As an interim control, ensure Skype is never run from untrusted directories and consider using application whitelisting to block loading of DLLs from user-writable locations.
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- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2016-5720 — 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-2016-5720 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
- No spam, self-promotion, credentials, or personal data