Skype for Business and Microsoft Lync
CVE-2019-1029 — Skype for Business and Lync Server Denial of Service Vulnerability
Executive Summary
A denial of service vulnerability exists in Skype for Business. An attacker who successfully exploited the vulnerability could cause Skype for Business to stop responding. Note that the denial of service would not allow an attacker to execute code or to elevate the attacker's user rights. To exploit the vulnerability, an attacker needs to obtain a dial-in link for a vulnerable server and then initiates a series of calls within a short amount of time. The update addresses the vulnerability by correcting the way that Skype for Business server handles objects in memory.
Overview
5.9
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
ATTACK VECTOR
Network
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
EPSS Score
0.05281
probability of exploitation in the next 30 days
0.91845 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
2 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft Lync Server 2010 | 4506009 (Security Update) |
Important | Denial of Service | Maybe |
| Microsoft Lync Server 2013 | 4506009 (Security Update) |
Important | Denial of Service | Maybe |
Patches
1 patch
| Article | Type | Restart |
|---|---|---|
4506009 |
Security Update | Maybe |
Exploits & PoC
No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.
Detection Rules
No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.
Acknowledgments
None
References
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