CVE-2016-1017 in Flash Player
Summary
by MITRE • 01/26/2023
Use-after-free vulnerability in the LoadVars.decode function in Adobe Flash Player before 18.0.0.343 and 19.x through 21.x before 21.0.0.213 on Windows and OS X and before 11.2.202.616 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-1011, CVE-2016-1013, CVE-2016-1016, and CVE-2016-1031.
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Analysis
by VulDB Data Team • 01/26/2023
The CVE-2016-1017 vulnerability represents a critical use-after-free flaw within Adobe Flash Player's LoadVars.decode function, affecting multiple versions across different operating systems. This vulnerability falls under the CWE-416 category of Use After Free, where memory that has been freed is accessed, potentially leading to arbitrary code execution. The affected versions include Flash Player 18.0.0.343 and earlier, 19.x versions through 21.x before 21.0.0.213 on Windows and OS X platforms, and Linux versions before 11.2.202.616. The vulnerability is distinct from several other related issues including CVE-2016-1011, CVE-2016-1013, CVE-2016-1016, and CVE-2016-1031, indicating it operates through different exploitation vectors.
The technical implementation of this vulnerability stems from improper memory management within the LoadVars.decode function which processes data received from external sources. When Flash Player processes malformed or specially crafted data through this function, it can cause memory to be freed while still being referenced elsewhere in the application's execution flow. Attackers can exploit this by crafting malicious content that triggers the vulnerable code path, leading to a situation where freed memory locations are accessed and potentially overwritten with malicious code. This allows for remote code execution with the privileges of the Flash Player process, which typically runs with the same permissions as the user.
From an operational perspective, this vulnerability presents significant risk to organizations due to Flash Player's widespread deployment across enterprise environments and the difficulty in maintaining complete visibility into all Flash content usage. The exploitability of this vulnerability through unspecified vectors suggests that attackers could leverage various attack surfaces including web browsers, email clients, and other applications that embed Flash content. The impact extends beyond individual user compromise to potentially enable lateral movement within networks, as attackers could use this vulnerability to establish persistent access points. This aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation.
Organizations should implement immediate mitigations including disabling Flash Player in web browsers and removing Flash content from all systems where possible. The recommended approach involves updating to patched versions of Adobe Flash Player, specifically versions 18.0.0.343, 21.0.0.213, and 11.2.202.616 respectively for each affected platform. Security teams should also deploy network-based intrusion detection systems to monitor for exploitation attempts and consider implementing browser security policies that prevent Flash content from executing automatically. Additionally, endpoint protection solutions should be configured to detect and block suspicious memory access patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of keeping multimedia frameworks updated and highlights the need for comprehensive application whitelisting policies to prevent execution of untrusted Flash content.