Zero-day vulnerability in Adobe Flash Player

Use-after-free error
CVE-2015-5119

The exploit code was revealed after Hacking Team data leak. Was also used in phishing campaigns conducted by two Chinese advanced persistent threat (APT) groups: APT3 and APT18.
The vulnerability was reported by Google Project Zero and Morgan Marquis-Boire.

Vulnerability details

Advisory: SB2015070701 - Remote code execution in Adobe Flash Player

Vulnerable component: Adobe Flash Player

CVE-ID: CVE-2015-5119

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 use-after-free error when processing .swf files. 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 of  the vulnerability results in arbitrary code execution on the vulnerable system.

Note: the vulnerability was being actively exploited.

Known APT campaigns:

BlackTech group

BlackTech group is a cyber espionage group mainly targeting companies in East Asia, particularly Taiwan, and occasionally, Japan and Hong Kong.

The threat group is linked to PLEAD in 2012, Shrouded Crossbow in 2010, and Waterbear cyber operations. To perform attacks BlackTech used a novel right-to-left override (RTLO) technique.

Public Exploits:

- Adobe Flash Player - ByteArray Use-After-Free (Metasploit) [Exploit-DB]

External links:

https://helpx.adobe.com/security/products/flash-player/apsb15-16.html
https://helpx.adobe.com/security/products/flash-player/apsa15-03.html
http://securityaffairs.co/wordpress/38707/cyber-crime/phishing-cve-2015-5119.html

https://www.zscaler.com/blogs/research/adobe-flash-vulnerability-cve-2015-5119-analysis
https://www.fireeye.com/blog/threat-research/2015/07/demonstrating_hustle.html
http://www.bankinfosecurity.com/zero-day-exploit-alert-flash-java-a-8396
https://www.zscaler.com/blogs/research/adobe-flash-vulnerability-cve-2015-5119-analysis
https://www.trustwave.com/Resources/SpiderLabs-Blog/A-Flash-Exploit-(CVE-2015-5119)-From-the-Hacking...
http://null-byte.wonderhowto.com/how-to/hack-like-pro-use-hacking-teams-adobe-flash-exploit-0163051/
http://blog.trendmicro.com/trendlabs-security-intelligence/hacking-team-flash-zero-day-integrated-in...
https://krebsonsecurity.com/2015/07/adobe-to-patch-hacking-teams-flash-zero-day/#more-31458
https://blog.malwarebytes.com/threat-analysis/2015/07/hacking-team-leak-exposes-new-flash-zero-day/
https://www.scmagazine.com/adobe-fixes-flash-player-zero-day-bug-identified-in-hacking-team-leak/art...

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.