LyncApplication · Microsoft

CVE-2018-8311

HIGH · 8.8 CVSS v3.0 Published 2018-07-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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
A remote code execution vulnerability exists when Skype for Business and Microsoft Lync clients fail to properly sanitize specially crafted content, aka "Remote Code Execution Vulnerability in Skype For Business and Lync." This affects Skype, Microsoft Lync.

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

A remote code execution vulnerability exists in Skype for Business and Microsoft Lync clients due to improper sanitization of specially crafted content. An attacker could exploit this by sending specially crafted content (likely via instant messages or other communication channels) that triggers code execution on the vulnerable client.

MitigationApply the relevant Microsoft security updates for Skype for Business and Lync clients to remediate the improper content sanitization vulnerability.

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
LyncApplication
Affected:all versions
Skype For BusinessApplication
Affected:all versions

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:3.0/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check if Skype for Business is installed
    Open Windows Settings > Apps > Apps & features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' in PowerShell to list installed applications. Look for 'Skype for Business' in the list.
    Affected if Skype for Business appears in the installed programs list, regardless of version
  2. Check if Microsoft Lync is installed
    Run the same PowerShell command or check Programs and Features in Control Panel. Look for 'Microsoft Lync' or 'Microsoft Lync 2010' / 'Microsoft Lync 2013' entries.
    Affected if Microsoft Lync appears in the installed programs list, regardless of version
  3. Verify the installed version number
    If either product is installed, right-click the application in the Start menu and select 'Open file location', then right-click the executable and select 'Properties' > 'Details' to view the version. Alternatively, open the client, go to Help > About Microsoft Lync / Skype for Business.
    Affected if Any version number is displayed, confirming the client is present (all versions are affected per CVE details)

If either Microsoft Lync or Skype for Business client is installed on the system, the environment is affected by this vulnerability since all versions are impacted.

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

Apply the relevant Microsoft security updates for Skype for Business and Lync clients to remediate the improper content sanitization vulnerability.

Fix this in Lync Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-8311 — 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-2018-8311 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