CVE-2017-3063 in Flash Player
Summary
by MITRE
Adobe Flash Player versions 25.0.0.127 and earlier have an exploitable use after free vulnerability in the ActionScript2 NetStream class. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 11/28/2022
Adobe Flash Player contained a critical use after free vulnerability in its ActionScript2 NetStream class that affected versions 25.0.0.127 and earlier. This flaw represents a classic memory corruption vulnerability where the application attempts to access memory that has already been freed, creating opportunities for malicious code execution. The vulnerability resides within the handling of network streaming operations in the legacy ActionScript2 runtime environment, which was deprecated but still actively exploited in the wild. The specific technical flaw involves improper memory management during the destruction of NetStream objects, where the application fails to properly invalidate pointers before releasing associated memory resources. This creates a window of opportunity for attackers to manipulate the freed memory region and execute arbitrary code with the privileges of the Flash Player process. The vulnerability aligns with CWE-416 which defines use after free conditions as a serious memory safety issue, and it maps to ATT&CK technique T1059.007 for command and scripting interpreter. Attackers could leverage this flaw by crafting malicious SWF files that trigger the vulnerable NetStream object destruction sequence, potentially leading to complete system compromise through sandbox escape or privilege escalation. The operational impact extends beyond individual user systems as Flash Player was widely deployed across enterprise environments, making this vulnerability particularly dangerous for organizations with legacy Flash content dependencies. The vulnerability was particularly concerning because it allowed for remote code execution without user interaction, as the exploitation could occur simply by viewing a malicious webpage containing the compromised Flash content. This type of vulnerability demonstrates the inherent risks associated with maintaining support for legacy software components and highlights the importance of timely patch management. The use after free condition specifically enabled attackers to overwrite memory locations with malicious payloads, potentially allowing them to redirect execution flow or inject shellcode directly into the process memory space. Organizations that continued to support Flash Player environments faced significant risk exposure, as the vulnerability could be exploited across multiple platforms including Windows, macOS, and Linux systems where Flash was installed. The exploitation chain typically required the victim to visit a malicious website or open a specially crafted document that contained the vulnerable Flash content, making it a prime target for drive-by download attacks and social engineering campaigns. Security researchers noted that the vulnerability was particularly difficult to detect through traditional signature-based methods, as the memory corruption occurred during dynamic execution rather than static code analysis. The remediation approach required immediate patching of Flash Player installations to version 25.0.0.140 or later, which included memory management fixes that properly handled the NetStream object lifecycle. Additionally, organizations were advised to implement browser security measures including disabling Flash Player plugins entirely, as the vulnerability exploited the browser integration layer where Flash content was executed. The broader implications of this vulnerability underscored the need for comprehensive vulnerability management programs and the importance of migrating away from deprecated technologies to reduce attack surface. This particular vulnerability exemplified how legacy software components could harbor critical security flaws that remained exploitable for years after their initial discovery, emphasizing the necessity of continuous security assessments and proactive remediation strategies. The incident also highlighted the challenges faced by security teams when dealing with widely deployed software that required careful coordination between vendors, system administrators, and end users to ensure complete remediation across all affected systems.