CVE-2017-2932 in Flash Player
Summary
by MITRE
Adobe Flash Player versions 24.0.0.186 and earlier have an exploitable use after free vulnerability in the ActionScript MovieClip class. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 04/20/2025
Adobe Flash Player contained a critical use after free vulnerability in its ActionScript MovieClip class that affected versions 24.0.0.186 and earlier. This vulnerability arises from improper memory management where freed memory blocks are still referenced or accessed by subsequent operations within the Flash Player runtime environment. The flaw specifically manifests when the MovieClip class handles object destruction and memory deallocation, creating a window where malicious code can manipulate freed memory pointers before they are properly invalidated. Attackers can exploit this condition by crafting specially designed Flash content that triggers the vulnerable code path, causing the application to execute arbitrary code with the privileges of the Flash Player process. The vulnerability is particularly dangerous because it allows remote code execution without requiring user interaction beyond visiting a malicious webpage containing the exploit. This type of vulnerability falls under the CWE-416 category of use after free conditions and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The memory corruption occurs at the application level within Flash Player's ActionScript runtime, making it difficult to detect through traditional network-based security measures. Successful exploitation can result in complete system compromise, as the malicious code executes within the context of the Flash Player process which typically has extensive privileges on the target system.
The technical implementation of this vulnerability involves the improper handling of reference counting and object lifecycle management within the MovieClip class. When a MovieClip object is destroyed, the memory allocated for that object is freed but references to the object may persist in other parts of the application's memory space. An attacker can manipulate these dangling pointers through carefully constructed ActionScript code that leverages the object's methods or properties after destruction has occurred. The vulnerability is particularly challenging to mitigate because it operates at a low level within the Flash Player's virtual machine, making it resistant to typical application-level security controls. The use after free condition creates a predictable memory layout that attackers can exploit to overwrite critical function pointers or execute shellcode directly in memory. This exploitability is amplified by the widespread deployment of Flash Player across various operating systems and the fact that many applications continue to rely on Flash content for multimedia functionality. The vulnerability demonstrates a classic memory safety issue where the runtime environment fails to properly invalidate object references, creating opportunities for attackers to manipulate the program flow through memory corruption.
The operational impact of CVE-2017-2932 extends far beyond individual system compromises, as Flash Player was widely deployed across enterprise networks and consumer environments. Organizations running vulnerable versions of Flash Player faced significant risk of lateral movement and persistent threats, as attackers could use this vulnerability to establish footholds within networks and maintain access over extended periods. The remote execution capability means that exploitation could occur without any user interaction, making it particularly dangerous for targeted attacks against high-value assets. Security professionals had to implement emergency patches and temporary workarounds while waiting for official updates from Adobe, which created operational challenges for maintaining business continuity. The vulnerability also highlighted the broader risks associated with legacy multimedia plugins and the difficulty of maintaining security for deprecated software components. Organizations with extensive Flash content deployments faced complex migration challenges, as they needed to identify and remediate all vulnerable instances while ensuring that legitimate business applications continued to function properly.
Mitigation strategies for this vulnerability required immediate patching of Flash Player installations and implementation of network-based controls to block Flash content delivery. Organizations should have deployed web application firewalls and content filtering solutions to prevent access to malicious Flash content, while also implementing strict browser security policies that disabled Flash plugin execution. System administrators needed to conduct comprehensive inventory audits to identify all vulnerable Flash Player installations across their networks and prioritize remediation efforts based on risk assessment. The vulnerability underscored the importance of maintaining up-to-date security patches and implementing application whitelisting controls to prevent execution of unauthorized code. Additionally, organizations should have reviewed their incident response procedures to ensure they could effectively detect and respond to exploitation attempts targeting this vulnerability. Long-term mitigation included migrating from Flash-based content to modern web standards such as html5 and javascript, which eliminated the attack surface associated with the Flash Player runtime environment. The incident also reinforced the need for regular security assessments of legacy applications and the importance of maintaining security awareness regarding deprecated software components that continue to pose significant risks to organizational security postures.