Medium severity · published May 11, 2021
CVE-2021-26421
Skype for Business and Lync Spoofing Vulnerability
6.5
CVSS
1.4%
EPSS
No
On KEV
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.4% · higher than 73% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LS
Lync Server · Microsoft
2013 · source: NVD
SF
Skype For Business Server · Microsoft
2015 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-26421
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-26421
Patch
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26421
More from Lync Server
7.2
CVE-2022-33633
Skype for Business and Lync Remote Code Execution Vulnerability
7.2
CVE-2021-26422
Skype for Business and Lync Remote Code Execution Vulnerability
6.5
CVE-2022-26911
Skype for Business Information Disclosure Vulnerability
6.5
CVE-2021-24099
Skype for Business and Lync Denial of Service Vulnerability
6.5
CVE-2021-24073
Skype for Business and Lync Spoofing Vulnerability