Zero-day vulnerability in Windows

NULL pointer dereference
CVE-2019-1132

The vulnerability was discovered by ESET in June 2019 when investigating a highly targeted attack in Eastern Europe.The vulnerability was used in a targeted attack against governmental institutions in Russia by an adversary known as Buhtrap.

Known IoCs:
sha1: CBC93A9DD769DEE98FFE1F43A4F5CADAF568E321

Known malware:

Win32/Exploit.CVE-2019-1132.A
VBA/TrojanDropper.Agent.ABM
VBA/TrojanDropper.Agent.AGK
Win32/Spy.Buhtrap.W
Win32/Spy.Buhtrap.AK
Win32/RiskWare.Meterpreter.G

Vulnerability details

Advisory: SB2019070905 - Privilege escalation in Microsoft Windows Win32k component

Vulnerable component: Windows

CVE-ID: CVE-2019-1132

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

CWE-ID: CWE-476 - NULL Pointer Dereference

Description:

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

The vulnerability exists due to a NULL pointer dereference  error when processing objects in memory within the Win32k component. A local user can create a malicious application, launch it on the system and execute arbitrary code with SYSTEM privileges.

Note, this vulnerability is being actively exploited in the wild.

External links:

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.