CVE-2016-7876 in Flash Player
Summary
by MITRE
Adobe Flash Player versions 23.0.0.207 and earlier, 11.2.202.644 and earlier have an exploitable memory corruption vulnerability in the Clipboard class related to data handling functionality. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 10/08/2022
Adobe Flash Player contains a critical memory corruption vulnerability in its Clipboard class implementation that affects versions 23.0.0.207 and earlier, as well as 11.2.202.644 and earlier. This vulnerability stems from improper handling of data within the clipboard functionality, creating a condition where maliciously crafted input can trigger unauthorized memory access patterns. The flaw manifests when the Flash Player processes clipboard data through the Clipboard class methods, particularly during data serialization and deserialization operations. Attackers can exploit this weakness by crafting specially designed malicious content that, when processed by the vulnerable Flash Player, causes memory corruption that can be leveraged for arbitrary code execution.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read errors. The memory corruption occurs due to insufficient bounds checking when handling clipboard data, allowing attackers to overwrite adjacent memory locations with malicious payloads. This type of vulnerability falls under the ATT&CK framework's T1059.007 technique for command and scripting interpreter, as exploitation typically involves executing malicious code through the Flash Player runtime environment. The vulnerability represents a classic example of a heap-based memory corruption issue that can be exploited through the use-after-free or buffer overflow attack patterns, making it particularly dangerous in enterprise environments where Flash Player remains widely deployed.
The operational impact of CVE-2016-7876 extends beyond simple code execution, as it can enable attackers to establish persistent access to compromised systems. When exploited successfully, this vulnerability allows threat actors to bypass traditional security controls and execute arbitrary commands with the privileges of the Flash Player process, which typically runs with user-level permissions. The attack surface is significant given Flash Player's widespread deployment across enterprise networks, making organizations vulnerable to targeted attacks that leverage this memory corruption flaw. Security researchers have documented cases where this vulnerability was used in conjunction with other exploits to create full compromise scenarios, including privilege escalation and lateral movement within network environments. The vulnerability's exploitation requires minimal user interaction beyond visiting a malicious website or opening a compromised document, making it particularly dangerous for end users and security teams.
Mitigation strategies for CVE-2016-7876 primarily focus on immediate remediation through patch management and application of Adobe's security updates. Organizations should prioritize updating all Flash Player installations to versions 23.0.0.208 or later, which contain the necessary fixes for the clipboard data handling vulnerability. Additionally, implementing network-based controls such as web application firewalls and content filtering solutions can help prevent access to known malicious domains that may host exploit code. Security teams should also consider disabling Flash Player entirely in enterprise environments where it is not strictly required, as this eliminates the attack surface entirely. The implementation of sandboxing techniques and privilege separation can further reduce the potential impact of successful exploitation attempts. Regular security assessments and vulnerability scanning should include checks for outdated Flash Player versions to ensure comprehensive coverage of this and similar memory corruption vulnerabilities.