Multiple vulnerabilities in Microsoft Windows Secure Socket Tunneling Protocol (SSTP)

Published: 2023-01-11

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2023-21535 CVE-2023-21548
CWE-ID	CWE-362
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Windows Operating systems & Components / Operating system Windows Server Operating systems & Components / Operating system
Vendor	Microsoft

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Race condition

EUVDB-ID: #VU71037

Risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-21535

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the system.

The vulnerability exists due to a race condition in Windows Secure Socket Tunneling Protocol (SSTP). A local user can exploit the race and execute arbitrary code on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows: 8.1 - 11 22H2

Windows Server: 2008 - 2022

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21535

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Race condition

EUVDB-ID: #VU71038