CVE-2016-7020 in Flash Player
Summary
by MITRE • 01/25/2023
Use-after-free vulnerability in Adobe Flash Player before 18.0.0.366 and 19.x through 22.x before 22.0.0.209 on Windows and OS X and before 11.2.202.632 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-4173, CVE-2016-4174, CVE-2016-4222, CVE-2016-4226, CVE-2016-4227, CVE-2016-4228, CVE-2016-4229, CVE-2016-4230, CVE-2016-4231, and CVE-2016-4248.
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Analysis
by VulDB Data Team • 10/05/2024
The CVE-2016-7020 vulnerability represents a critical use-after-free flaw in Adobe Flash Player that affected multiple version ranges across different operating systems. This vulnerability specifically impacted Windows and macOS versions prior to 18.0.0.366 and 19.x through 22.x before 22.0.0.209, as well as Linux versions before 11.2.202.632. The flaw resides in the memory management handling of Flash Player's runtime environment, creating a condition where freed memory locations could be accessed and potentially overwritten by malicious code. Such vulnerabilities are particularly dangerous because they can lead to arbitrary code execution when exploited, making them prime targets for cybercriminals seeking to compromise systems through web-based attacks.
The technical nature of this vulnerability falls under the CWE-416 category of "Use After Free" which describes a condition where a program continues to use a pointer to memory after it has been freed by the system. In the context of Flash Player, this occurs when the application allocates memory for objects and then frees that memory while still maintaining references to it. Attackers can exploit this by crafting malicious Flash content that triggers the use-after-free condition, potentially allowing them to manipulate the freed memory location to inject and execute malicious code with the privileges of the Flash Player process. This exploitation technique aligns with ATT&CK framework tactic T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation.
The operational impact of CVE-2016-7020 was significant given Flash Player's widespread deployment across enterprise environments and user systems. The vulnerability could be exploited through web browsers that had Flash Player enabled, making it particularly dangerous as users could be compromised simply by visiting malicious websites or opening malicious email attachments containing Flash content. The fact that this vulnerability was distinct from other related CVEs in the same year indicates it was a separate code path that had not been previously addressed, making it a particularly concerning issue for security teams who had to maintain awareness of multiple related but distinct vulnerabilities. Organizations running affected versions of Flash Player faced potential full system compromise, as the arbitrary code execution capability could be leveraged to install backdoors, steal credentials, or deploy additional malware.
Mitigation strategies for CVE-2016-7020 centered around immediate patching of affected Flash Player versions, as Adobe released security updates addressing this specific vulnerability. System administrators were advised to disable Flash Player entirely where possible, given its history of security issues and the complexity of maintaining secure configurations. Network security controls such as web application firewalls and content filtering solutions were also recommended to block Flash content from untrusted sources. Additionally, endpoint detection and response solutions could help identify exploitation attempts by monitoring for unusual memory access patterns or process behavior that might indicate use-after-free exploitation. The vulnerability highlighted the importance of maintaining up-to-date software and the risks associated with legacy technologies like Flash Player that had become increasingly difficult to secure as they aged. Security teams were also encouraged to implement comprehensive vulnerability management processes that could identify and remediate similar issues in other software components, as the use-after-free pattern remains a common and dangerous class of vulnerability across software platforms.