Zero-day vulnerability in Windows

Information disclosure
CVE-2019-0703

Exploit code for this vulnerability was detected by Symantec when analyzing the Bemstour exploit tool in September 2018. Researchers make connection between the Buckeye (APT3) group and such exploit packs as Bemstour exploit tool and DoublePulsar.

Known malware:

Bemstour exploit tool

Vulnerability details

Advisory: SB2019031206 - Multiple vulnerabilities in Microsoft Windows SMB

Vulnerable component: Windows

CVE-ID: CVE-2019-0703

CVSSv3 score: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:H/RL:O/RC:C

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

Description:

The vulnerability allows a remote authenticated attacker to gain access to potentially sensitive information.

The vulnerability exists due to the way that the Windows SMB Server handles certain requests. A remote authenticated user can gain unauthorized access to sensitive information on the system.

Note: this vulnerability has being exploited in the wild. The exploit code was detected in the Bemstour exploit tool in September 2018 and has being used by Buckeye (APT3) APT group.

External links:

https://www.symantec.com/blogs/threat-intelligence/buckeye-windows-zero-day-exploit

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.