Computer Terrorism (UK) :: Incident Response Centre www.computerterrorism.com Security Advisory: CT12-09-2006 ============================================================ Adobe/Macromedia Flash Player - Remote Code Execution ============================================================ Advisory Date: 12th, September 2006 Severity: Critical Impact: Remote System Access Solution Status: Vendor Patch CVE Reference: CVE-2006-3311 Affected Software ================= Adobe Flash Player 8.0.24.0 and earlier versions Adobe Flash Professional 8, Flash Basic Adobe Flash MX 2004 Adobe Flex 1.5 Note: All OS Platforms are vulnerable 1. OVERVIEW =========== Adobe/Macromedia Flash Player is the world's most ubiquitous Browser plug-in for Microsoft, Mozilla and Apple technologies. The plug-in claims to facilitate high-impact web interfaces and interactive online advertising for circa 98% of desktops globally. Unfortunately, it transpires that Adobe Flash Player is prone to a remote arbitrary code execution vulnerability, that allows an attacker to gain control of a target system through the simple invocation of a maliciously constructed web page. 2. TECHNICAL NARRATIVE ====================== The vulnerability originates out of Flash's failure to sufficiently handle large dynamically generated strings at run time. As a result, it is possible (using rudimentary Action Script) to create a .swf movie in such a way that when processed by the Plug-in, will overwrite system memory at an explicit location. More specifically, the aforementioned location can (with a certain degree of accuracy) be attacker controlled via the direct manipulation of the overall length of the generated string. The net result is that of a partially controllable condition, which opens the door to a multitude of differing exploitation vectors, including but not limited to heap/stack overwrites, and/or 3rd party race conditions. 3. EXPLOITATION =============== Computer Terrorism (UK) can confirm the un-disclosed production of a reliable multi-platform & multi-browser Web based Proof-Of-Concept (PoC). Such an exploit could be used in a web-based attack scenario, where unsuspecting users are lured to a maliciously constructed website. Users that have not already done so are strongly advised to upgrade to the latest version of Flash Player or apply the appropriate fix for their particular version. 4. VENDOR RESPONSE ================== The vendor security bulletin and corresponding patches are available at the following location: http://www.adobe.com/go/apsb06-11/ 5. DISCLOSURE ANALYSIS ====================== 12/05/2006 Preliminary Vendor notification. 18/05/2006 Vulnerability confirmed in pre-release Flash 9, and earlier versions 28/06/2006 Flash Player 9 released (Fixed) 31/07/2006 Public Disclosure Deferred by Vendor. 12/09/2006 Coordinated public release. Total Time to Fix: 4 months (123 days) 6. CREDIT ========= The vulnerability was discovered by Stuart Pearson of Computer Terrorism (UK) Ltd =================== About Computer Terrorism =================== Computer Terrorism (UK) Ltd is a global provider of Digital Risk Intelligence services. Our unique approach to vulnerability risk assessment and mitigation has helped protect some of the worlds most at risk organisations. Headquartered in London, Computer Terrorism has representation throughout Europe & North America and can be reached at +44 (0) 870 250 9866 or email:- sales [at] computerterrorism.com To learn more about our services and to register for a FREE comprehensive website penetration test, visit: http:/www.computerterrorism.com Computer Terrorism (UK) :: Protection for a vulnerable world.