Zero-day vulnerability in Windows

Buffer overflow
CVE-2017-0176

The vulnerability was disclosed by the Shadow Brokers hacking team.

Known malware:

EsteemAudit

Vulnerability details

Advisory: SB2017051217 - Buffer overflow in Microsoft Windows RDP for Windows XP/2003

Vulnerable component: Windows

CVE-ID: CVE-2017-0176

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

CWE-ID: CWE-119 - Memory corruption

Description:

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error in the Smart Card authentication code in gpkcsp.dll within Windows Remote Desktop services. A remote attacker can send specially crafted packets to the vulnerable system, trigger buffer overflow and execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to gain complete control over the affected system.

Note: this vulnerability was publicly disclosed by the Shadow Brokers hacking team along with a fully functional exploit known as "тАЬEsteemAudit".

The vulnerability is being exploited in the wild.


External links:

https://blog.fortinet.com/2017/05/11/deep-analysis-of-esteemaudit
https://support.microsoft.com/en-us/help/4022747/security-update-for-windows-xp-and-windows-server-2003

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.