Zero-day vulnerability in Microsoft Office

Memory corruption
CVE-2015-1642

The vulnerability was discovered by Yong Chuan, Koh of MWR Labs.

Vulnerability details

Advisory: SB2015081102 - Multiple vulnerabilities in Microsoft Office

Vulnerable component: Microsoft Office

CVE-ID: CVE-2015-1642

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 execute arbitrary code on the target system.

The vulnerability exists due to boundary error when processing Microsoft Office documents. A remote unauthenticated attacker can create a specially crafted Office document, trick the victim into opening it and execute arbitrary code on the target system with privileges of the current user.

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

Note: this vulnerability is being actively exploited.

External links:

https://technet.microsoft.com/en-us/library/security/ms15-081.aspx
https://www.symantec.com/security_response/vulnerability.jsp?bid=76200
https://www.nccgroup.trust/uk/our-research/understanding-microsoft-word-ole-exploit-primitives/
https://labs.mwrinfosecurity.com/advisories/microsoft-office-ctasksymbol-use-after-free-vulnerabilit...
http://blog.trendmicro.com/trendlabs-security-intelligence/august-patch-tuesday-includes-update-for-....

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.