Main Vulnerability Database Vulnerabilities #VU53103

Spoofing attack in Microsoft Lync and Skype for Business Server - CVE-2021-26421

Published: May 11, 2021

Vulnerability identifier: #VU53103

CSH Severity: Medium

CVSS v4: 5.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-26421

CWE-ID: CWE-451

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data in Skype for Business and Lync. A remote authenticated attacker can spoof page content.

Affected software

Microsoft Lync
Skype for Business Server

How to mitigate CVE-2021-26421

Install updates from vendor's website.

External References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26421

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