Zero-day vulnerability in Microsoft Internet Explorer

Memory corruption
CVE-2016-3351

Microsoft has known about CVE-2016-3351 since 2015.
Exploited By AdGholas and GooNky Malvertising Groups.

Vulnerability details

Advisory: SB2016091307 - Multiple vulnerabilities in Microsoft Internet Explorer and Edge

Vulnerable component: Microsoft Internet Explorer

CVE-ID: CVE-2016-3351

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

CWE-ID: CWE-119 - Memory corruption

Description:

The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists due to boundary error when handling of malicious files. A remote attacker can create a specially crafted content, trick the victim into opening it, trigger memory corruption and gain access to arbitrary data.

Successful exploitation of the vulnerability results in information disclosure on the vulnerable system.

Note: the vulnerability was being actively exploited.

Known APT campaigns:

AdGholas

AdGholas is a name of malvertising campaign active since at least October 2015. To avoid detection the hackers use steganography and file whitelisting techniques. As of April 2017 the hackers employed Astrum exploit kit, according to Trend Micro report.

External links:

https://www.proofpoint.com/us/threat-insight/post/Microsoft-Patches-Zero-Day-Exploited-By-AdGholas-G...
https://technet.microsoft.com/library/security/ms16-104
https://technet.microsoft.com/library/security/MS16-105
https://www.symantec.com/security_response/attacksignatures/detail.jsp?asid=29628
http://blog.trendmicro.com/trendlabs-security-intelligence/cve-2016-3298-microsoft-fixes-another-ie-...
http://securityaffairs.co/wordpress/51494/hacking/internet-explorer-exploits.html
http://wccftech.com/zero-day-exploited-update-windows-right-away/
https://www.brokenbrowser.com/detecting-local-files-to-evade-analysts/
http://www.securityweek.com/microsoft-patches-browser-vulnerability-exploited-attacks
https://www.scmagazineuk.com/microsoft-bundles-security-updates--no-more-pick-and-choose/article/547...
http://www.securingcomputer.com/news/microsoft-patches-browser-vulnerability-exploited-attacks
http://www.zdnet.com/article/microsoft-patches-critical-ie-bug-that-was-under-attack-for-nearly-thre...
http://techgenix.com/microsoft-patches-ie-malvertising-vulnerability/

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.