Zero-day vulnerability in Microsoft Office

Buffer overflow
CVE-2006-3649

The weakness was disclosed 08/08/2006 by Ka Chun Leung with Symantec.

Known malware:

Trojan.Mdropper.N

Vulnerability details

Advisory: SB2006080801 - Remote code execution in Microsoft VBA

Vulnerable component: Microsoft Office

CVE-ID: CVE-2006-3649

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

CWE-ID: CWE-119 - Memory corruption

Description:

The vulnerability allows a remote user to execute arbitrary code on the target system.

The weakness is due to buffer overflow. By persuading the victim to open a malicious Office document containing Visual Basic for Applications (VBA) script, a remote attacker can execute arbitrary code.
Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.

Note: this vulnerability was being actively exploited.

External links:

http://www.microsoft.com/technet/security/Bulletin/MS06-047.mspx
ftp://ftp.cerias.purdue.edu/pub/advisories/ciac/q-fy06/q-274.Vul.in.Microsoft.Visual.Basic.txt
https://www.trendmicro.com/vinfo/us/threat-encyclopedia/archive/security-advisories/(ms06-047)%20vul...
https://www.symantec.com/content/en/us/enterprise/collateral/tech_briefs/11310863_HTTST_tb.pdf

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.