The Server in Microsoft Lync Server 2013 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon hang) via a crafted request, aka "Lync Denial of Service Vulnerability."
Conclusion & alert: CVE-2014-4071 is rated Moderate Risk (48.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 18.99%, 97th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 31.15% | 18.99% | -12.16% |
| 2 | 2025-03-30 | 48.55% | 31.15% | -17.40% |
| 3 | 2025-03-29 | — | 48.55% | — |
Full EPSS history (13 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
: <a href="http://cwe.mitre.org/data/definitions/476.html">CWE-476: NULL Pointer Dereference</a>
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | lync_server | 2013 | cpe:2.3:a:microsoft:lync_server:2013:*:*:*:*:*:*:* |