CVE-2015-3121 in Flash Player
Summary
by MITRE
Adobe Flash Player before 13.0.0.302 and 14.x through 18.x before 18.0.0.203 on Windows and OS X and before 11.2.202.481 on Linux, Adobe AIR before 18.0.0.180, Adobe AIR SDK before 18.0.0.180, and Adobe AIR SDK & Compiler before 18.0.0.180 allow attackers to execute arbitrary code by leveraging an unspecified "type confusion," a different vulnerability than CVE-2015-3119, CVE-2015-3120, CVE-2015-3122, and CVE-2015-4433.
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Analysis
by VulDB Data Team • 05/23/2022
Adobe Flash Player and AIR runtime environments suffered from a critical type confusion vulnerability that enabled remote code execution attacks. This flaw existed in multiple versions across different platforms including Windows, macOS, and Linux operating systems. The vulnerability stemmed from improper handling of object types during runtime execution, creating opportunities for attackers to manipulate memory structures and execute malicious code with the privileges of the Flash Player process. Type confusion vulnerabilities typically occur when a program uses an object in a manner inconsistent with its actual type, leading to unpredictable behavior and potential exploitation. The specific nature of this vulnerability involved the Flash Player's ActionScript virtual machine failing to properly validate type information during object manipulation, allowing attackers to craft specially crafted SWF files that could trigger the flaw when executed. This vulnerability was distinct from several related issues including CVE-2015-3119 through CVE-2015-4433, indicating it represented a separate code path that required different exploitation techniques. The attack vector involved delivering a malicious Flash content file through web browsers or other means that would cause the vulnerable Flash Player to process the content, ultimately leading to arbitrary code execution on the target system. The impact extended beyond simple code execution as attackers could leverage this vulnerability to bypass security restrictions, escalate privileges, and potentially gain full system control. This flaw particularly affected enterprise environments where Flash Player was commonly installed and used, making it a significant concern for organizations with extensive Flash-based applications. The vulnerability aligns with CWE-476 which describes null pointer dereference conditions, though the specific implementation involved type confusion rather than simple null dereference. From an operational perspective, this vulnerability required minimal user interaction to exploit, often only requiring the user to visit a compromised website that delivered the malicious Flash content. The exploitation process typically involved crafting a SWF file with carefully constructed object types that would cause the Flash Player to misinterpret memory layout, leading to code execution. Organizations needed to urgently patch their systems as the vulnerability had been actively exploited in the wild. The attack pattern followed common threat actor methodologies where the initial compromise occurred through web-based delivery mechanisms, leveraging the widespread use of Flash Player across various platforms. Security researchers identified this vulnerability as particularly dangerous due to its potential for privilege escalation and the fact that it could be triggered without requiring user interaction beyond visiting a malicious website. The fix required updating to specific patched versions of Adobe Flash Player and AIR runtime environments, with different version requirements for each platform. Organizations had to carefully coordinate these updates across their enterprise environments to ensure complete protection. The vulnerability also highlighted the broader security concerns surrounding legacy Flash Player implementations and the challenges of maintaining secure runtime environments for deprecated technologies. This issue demonstrated the importance of proper type validation in virtual machine implementations and the potential consequences when such validation is insufficient. The vulnerability had significant implications for security teams who had to balance the need for immediate patching with the operational impact of updating widely deployed Flash Player installations. The exploitation techniques used against this vulnerability aligned with ATT&CK tactic T1059 which covers command and scripting interpreter usage, as attackers could execute arbitrary code through the Flash Player runtime environment. The widespread deployment of Flash Player across enterprise networks made this vulnerability particularly concerning for security operations, requiring coordinated response efforts to address the risk across multiple systems and platforms.