#VU29729 Buffer overflow


Published: 2020-07-14 | Updated: 2020-07-15

Vulnerability identifier: #VU29729

Vulnerability risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-1025

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Skype for Business Server
Server applications / Conferencing, Collaboration and VoIP solutions
Microsoft Lync
Client/Desktop applications / Messaging software
Microsoft SharePoint Server
Server applications / Application servers

Vendor: Microsoft

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error when Microsoft SharePoint Server and Skype for Business Server improperly handle OAuth token validation. A local user can modify the token, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Skype for Business Server: 2015 CU8

Microsoft Lync:

Microsoft SharePoint Server: 2016 - 2019

Microsoft SharePoint Server: 2013


External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1025


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.


Latest bulletins with this vulnerability