CVE-2017-11786 Auth bypass in Skype for Business

What is CVE-2017-11786?

CVE-2017-11786 is a high-severity authentication bypass vulnerability in Microsoft Corporation Skype for Business, published on 13 Oct 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Skype for Business in Microsoft Lync 2013 SP1 and Skype for Business 2016 allows an attacker to steal an authentication hash that can be reused elsewhere, due to how Skype for Business handles authentication requests, aka "Skype for Business Elevation of Privilege Vulnerability."

Weakness: CWE-294

Which versions are affected by CVE-2017-11786?

It affects 2 products.

Products include Microsoft Lync, Microsoft Skype for Business.

How do I fix CVE-2017-11786?

No fix has been published for CVE-2017-11786 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2017-11786 being exploited?

There is no known exploitation of CVE-2017-11786 in the wild and no public exploit code.

Other vulnerabilities in Microsoft Corporation Skype for Business

• CVE-2020-1025 Microsoft Office Elevation of Privilege Vulnerability Critical 9.8
• CVE-2013-1302 Use after free in n/a Critical 9.3
• CVE-2012-1849 Path traversal in n/a Critical 9.3
• CVE-2018-8311 Code injection in Microsoft Lync High 8.8
• CVE-2017-0283 Memory corruption in Uniscribe High 8.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-2xjh-35wj-vw46.