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.
## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Microsoft Lync Server 2010 | | [KB4506009](https://patchblox.com/security/data/fix/microsoft/kb4506009.md) | Jun 11, 2019 | | Microsoft | Microsoft Lync Server 2013 | | [KB4506009](https://patchblox.com/security/data/fix/microsoft/kb4506009.md) | Jun 11, 2019 | --- Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.