Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 2 |
CVE-ID | CVE-2021-26422 CVE-2021-26421 |
CWE-ID | CWE-94 CWE-451 |
Exploitation vector | Network |
Public exploit | N/A |
Vulnerable software Subscribe |
Skype for Business Server Server applications / Conferencing, Collaboration and VoIP solutions Microsoft Lync Client/Desktop applications / Messaging software |
Vendor | Microsoft |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
EUVDB-ID: #VU53102
Risk: Low
CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-26422
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote user to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation in Skype for Business and Lync. A remote administrator can execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsSkype for Business Server: 2015 CU11 - 2019 CU5
Microsoft Lync: 2013 CU10
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26422
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
EUVDB-ID: #VU53103
Risk: Medium
CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-26421
CWE-ID:
CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)
Exploit availability: No
DescriptionThe 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.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMicrosoft Lync: 2013 CU10
Skype for Business Server: 2015 CU11
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26421
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.