Zero-day vulnerability in Microsoft Internet Explorer

Memory corruption
CVE-2015-2502

The vulnerability has been exploited in watering hole attacks against compromised website belonging to an evangelical church in Hong Kong to deliver Korplug malware.

Known malware:

Korplug malware.

Vulnerability details

Advisory: SB2015081801 - Remote code execution in Microsoft Internet Explorer

Vulnerable component: Microsoft Internet Explorer

CVE-ID: CVE-2015-2502

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 Javascript and HTML tables within the layout cache. A remote attacker can create a specially crafted Web site, trick the victim into visiting it, trigger memory corruption and execute arbitrary code with privileges of the current user.

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

Note: the vulnerability was being actively exploited.

External links:

https://technet.microsoft.com/library/security/MS15-093
http://www.securityweek.com/microsoft-issues-emergency-patch-critical-ie-flaw-exploited-wild
https://www.symantec.com/security_response/attacksignatures/detail.jsp?asid=28195
https://www.alienvault.com/blogs/security-essentials/internet-explorer-memory-corruption-vulnerabili...
https://www.tripwire.com/state-of-security/vulnerability-management/ie-under-attack-microsoft-releas...
https://krebsonsecurity.com/2015/08/microsoft-pushes-emergency-patch-for-ie/
https://www.redpacketsecurity.com/cve-2015-2502-microsoft-issues-emergency-patch-for-all-versions-of...
https://blog.qualys.com/laws-of-vulnerabilities/2015/08/18/ms15-093--oob-fix-for-internet-explorer
https://arstechnica.com/security/2015/08/microsoft-issues-emergency-patch-for-critical-ie-bug-under-...
https://www.scmagazine.com/microsoft-patches-critical-remote-code-execution-bug-in-internet-explorer...
https://www.symantec.com/connect/tr/blogs/new-internet-explorer-zero-day-exploited-hong-kong-attacks
https://malwarelist.net/tag/zero-day-vulnerability/
http://www.darkreading.com/attacks-breaches/ie-bug-exploited-in-wild-after-microsoft-releases-out-of...
http://thehackernews.com/2015/08/microsoft-emergency-patch-zero-day-internet-explorer.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.