CVE-2018-8238

Skype for Business and Lync Security Feature Bypass Vulnerability

CVE-2018-8238 is fixed in 4 products on 1 platform, first by KB4022225, released July 10, 2018. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
n/a
Important
Exploitation
None reported
Exploitation Less Likely
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0599
93rd percentile

<p>A security feature bypass vulnerability exists when Skype for Business or Lync do not properly parse UNC path links shared via messages. An attacker who successfully exploited the vulnerability could execute arbitrary commands in the context of the logged-in user. The security feature bypass by itself does not allow arbitrary code execution. Instead, an attacker would have to convince users to click a link to a file.</p> <p>In a file-sharing attack scenario, an attacker could provide a specially-crafted file designed to exploit the vulnerability, and then convince a user to click the link to the file.</p> <p>The update addresses the vulnerability by correcting how Skype for Business and Lync handle links to UNC paths.</p>

Where it's fixed

ProductFixed inFixReleased
Microsoft
Microsoft Lync 2013 Service Pack 1 (32-bit) KB4022225 Jul 10, 2018
Microsoft Lync 2013 Service Pack 1 (64-bit) KB4022225 Jul 10, 2018
Skype for Business 2016 (32-bit) KB4022221 Jul 10, 2018
Skype for Business 2016 (64-bit) KB4022221 Jul 10, 2018