Zero-day vulnerability in Microsoft Office

Buffer overflow
CVE-2013-1331

The vulnerability was reported by Andrew Lyons and Neel Mehta of Google Inc.

Using the samples provided by Microsoft, Romang scoured GoogleтАЩs cache and found the earliest document that attempted to fetch the exploit dated from February, 2013. The document referenced territory disputes between China and the Philippines.
However, Romang uncovered another Word document created in 2009 that, according to GoogleтАЩs Virus Total service, would also exploit the flaw Microsoft patched. The fileтАЩs title тАЬThe corruption of MahathirтАЭ referred to a Malaysian politician, fitting MicrosoftтАЩs list of possible targets. Both documents to a Bridging Links URL.

The vulnerability might have been spotted in the wild, with campaigns starting as early as 2009. Microsoft believe attacks were limited to Indonesia and Malaysia.

Known malware:

Trojan.Mdropper.

Vulnerability details

Advisory: SB2013061101 - Remote code execution in Microsoft Office

Vulnerable component: Microsoft Office

CVE-ID: CVE-2013-1331

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 buffer overflow when processing malicious PNG files. A remote attacker can create specially crafted file, trick the victim into opening it using an affected version of Microsoft Office, trigger memory corruption and execute arbitrary code with privileges of the current user.

Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.

Note: the vulnerability was being actively exploited.

External links:

https://technet.microsoft.com/en-us/library/security/ms13-051.aspx
https://www.symantec.com/security_response/vulnerability.jsp?bid=60408
https://www.symantec.com/connect/blogs/microsoft-office-cve-2013-1331-coverage
https://media.paloaltonetworks.com/lp/endpoint-security/blog/cve-2013-1331-a-zero-day-disclosed.html
http://eromang.zataz.com/2013/06/13/ms13-051-cve-2013-1331-what-we-know-about-microsoft-office-zero-...
https://threatpost.com/important-office-2003-zero-day-deserves-second-look/100990/
https://blogs.technet.microsoft.com/srd/2013/06/11/ms13-051-get-out-of-my-office/
http://dataprotectioncenter.com/general/microsoft-office-cve-2013-1331-coverage/
http://blog.trendmicro.com/trendlabs-security-intelligence/light-june-2013-patch-tuesday-is-no-reaso...

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.