CVE-2016-6923 in Flash Player
Summary
by MITRE • 01/25/2023
Use-after-free vulnerability in Adobe Flash Player before 18.0.0.375 and 19.x through 23.x before 23.0.0.162 on Windows and OS X and before 11.2.202.635 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-4272, CVE-2016-4279, CVE-2016-6921, CVE-2016-6925, CVE-2016-6926, CVE-2016-6927, CVE-2016-6929, CVE-2016-6930, CVE-2016-6931, and CVE-2016-6932.
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Analysis
by VulDB Data Team • 01/25/2023
The CVE-2016-6923 vulnerability represents a critical use-after-free flaw in Adobe Flash Player affecting multiple version ranges across different operating systems. This vulnerability exists in Flash Player versions before 18.0.0.375 and 19.x through 23.x before 23.0.0.162 on Windows and OS X platforms, as well as before 11.2.202.635 on Linux systems. The flaw allows remote attackers to execute arbitrary code through unspecified attack vectors that differ from several other related vulnerabilities in the same timeframe, making it particularly dangerous due to its unique exploitation method.
The technical nature of this use-after-free vulnerability stems from improper memory management within the Flash Player runtime environment. When a Flash Player application processes certain malicious content, it may free memory associated with an object while still maintaining references to that memory location. Attackers can exploit this by crafting malicious SWF files that trigger the freeing of memory structures, then manipulating the freed memory to redirect execution flow or inject malicious code. This type of vulnerability falls under CWE-416, which specifically addresses use-after-free conditions in software development.
The operational impact of CVE-2016-6923 extends beyond typical web browser exploitation scenarios due to Flash Player's widespread deployment across enterprise environments. Organizations running vulnerable Flash Player versions face significant risk of remote code execution attacks that could lead to complete system compromise. The vulnerability's presence in multiple Flash Player versions across different platforms means that organizations cannot simply patch one specific version to address the issue, requiring comprehensive patch management across all affected systems. This vulnerability aligns with ATT&CK technique T1059.007 for Windows Command and Scripting Interpreter, as attackers could leverage the executed code to establish persistent access or escalate privileges.
Mitigation strategies for CVE-2016-6923 require immediate action including mandatory patch deployment for all affected Flash Player versions, along with network-level restrictions to prevent execution of Flash content where possible. Organizations should implement browser sandboxing mechanisms and consider disabling Flash Player entirely in production environments, given its history of vulnerabilities and the availability of modern web standards that reduce dependency on Flash-based content. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that reduce attack surface areas for known vulnerable components. Security teams should monitor for exploitation attempts through network traffic analysis and implement proper incident response procedures to handle potential compromise scenarios.