November 13, 2018
Microsoft Skype for Business and Lync are prone to a remote denial-of-service vulnerability. An attacker can exploit this issue to cause the target service to stop responding, denying service to legitimate users.
- Microsoft Lync 2013 (32-bit) SP1
- Microsoft Lync 2013 (64-bit) SP1
- Microsoft Lync Basic 2013 (32-bit) SP1
- Microsoft Lync Basic 2013 (64-bit) SP1
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft Office 365 ProPlus for 32-bit Systems
- Microsoft Office 365 ProPlus for 64-bit Systems
- Microsoft Skype for Business 2016 (32-bit)
- Microsoft Skype for Business 2016 (64-bit)
- Microsoft Skype for Business Basic 2016 (32-bit)
- Microsoft Skype for Business Basic 2016 (64-bit)
Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of suspicious or anomalous activity. This may help detect malicious actions that an attacker may take after successfully exploiting vulnerabilities in applications. Review all applicable logs regularly.
Do not use client software to access unknown or untrusted hosts from critical systems.
Due to the nature of this issue, avoid using the client application to connect to unknown or untrusted hosts.
Updates are available. Please see the references or vendor advisory for more information.
Sabine Degen of SEC Consult Vulnerability Lab.
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