Zero-day vulnerability in Microsoft Office

Memory corruption
CVE-2017-11826

The weakness was reported to Microsoft by researchers at China-based security firm Qihoo 360. The experts said they first observed an attack exploiting this vulnerability on September 28. The attacks targeted a small number of the companyтАЩs customers and they involved malicious RTF files.

Vulnerability details

Advisory: SB2017101001 - Remote code execution in Microsoft Office

Vulnerable component: Microsoft Office

CVE-ID: CVE-2017-11826

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 weakness exists due to boundary error when handling malicious content. A remote attacker can send a specially crafted .doc file, trick the victim into opening it, trigger memory corruption and execute arbitrary code with system privileges.

Successful exploitation of the vulnerability may result in system compromise.

Note: the vulnerability is being actively exploited.

External links:

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11826
http://360coresec.blogspot.ro/2017/10/new-office-0day-cve-2017-11826.html

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.