CVE-2017-2936 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 FileReference class. Successful exploitation could lead to arbitrary code execution.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2017-2936 represents a critical use after free flaw within Adobe Flash Player's ActionScript FileReference class implementation. This particular weakness exists in Flash Player versions 24.0.0.186 and earlier, making a substantial portion of the user base susceptible to exploitation. The FileReference class is commonly used in web applications to enable users to select and upload files from their local system to remote servers, which makes this vulnerability particularly dangerous as it can be triggered through normal web browsing activities. The flaw stems from improper memory management where the application continues to reference memory locations that have already been freed, creating opportunities for attackers to manipulate the execution flow of the application.
The technical nature of this vulnerability places it within the CWE-416 category of use after free conditions, which is classified as a memory safety issue in software development practices. When an attacker successfully exploits this vulnerability, they can achieve arbitrary code execution on the victim's system, potentially leading to complete system compromise. The exploitation process typically involves crafting malicious Flash content that triggers the use after free condition in the FileReference class, allowing the attacker to overwrite memory locations with malicious code. This type of vulnerability is particularly dangerous because it can be delivered through standard web traffic without requiring user interaction beyond visiting a compromised website, making it an ideal candidate for drive-by download attacks.
The operational impact of CVE-2017-2936 extends beyond simple code execution, as it represents a significant vector for advanced persistent threats and malware delivery. The vulnerability's exploitation aligns with techniques documented in the attack matrix under the T1059.007 sub-technique for command and scripting interpreter, where attackers can leverage the compromised Flash Player to execute malicious payloads. Organizations that rely on Flash Player for web applications, content management systems, or legacy web interfaces face substantial risk from this vulnerability. The widespread deployment of Flash Player across various platforms and applications means that exploitation can occur in multiple environments, from corporate networks to personal computing devices. This vulnerability also demonstrates the inherent risks of complex multimedia frameworks that handle user input through memory-intensive operations, where improper resource management can lead to complete system compromise.
Mitigation strategies for this vulnerability primarily focus on immediate remediation through software updates, as Adobe released patches for Flash Player versions beyond 24.0.0.186 to address the use after free condition. Organizations should implement comprehensive patch management procedures to ensure all Flash Player installations are updated promptly. Additional protective measures include network-based filtering to block Flash content, browser-based security controls such as sandboxing, and user education to avoid visiting untrusted websites. The vulnerability also highlights the importance of implementing secure coding practices and regular security assessments of multimedia frameworks. From an enterprise security perspective, organizations should consider implementing application whitelisting policies that restrict Flash Player execution to trusted environments only, while also monitoring network traffic for suspicious Flash-related activity that may indicate exploitation attempts.