CVE-2002-0846 in Shockwave Flash
Summary
by MITRE
The decoder for Macromedia Shockwave Flash allows remote attackers to execute arbitrary code via a malformed SWF header that contains more data than the specified length.
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Analysis
by VulDB Data Team • 09/05/2025
The vulnerability identified as CVE-2002-0846 represents a critical buffer overflow flaw in Macromedia Shockwave Flash decoders that enables remote code execution through malformed SWF file headers. This issue affects the way Flash players process Shockwave Flash files, specifically when handling the header structure where the actual data exceeds the length value specified in the file header. The flaw stems from insufficient input validation and boundary checking within the Flash decoder implementation, creating a condition where attackers can craft malicious SWF files that trigger memory corruption during file parsing operations. This vulnerability is particularly dangerous because it can be exploited through web browsers that have Flash plugin support, allowing attackers to execute arbitrary code on vulnerable systems without requiring user interaction beyond visiting a malicious website.
The technical implementation of this vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations. The flaw manifests when the Flash decoder reads the file header and parses the length field, subsequently allocating memory based on this value. However, when the actual data content exceeds the declared length, the decoder continues processing beyond allocated memory boundaries, leading to potential memory corruption that can be leveraged by attackers to inject and execute malicious code. This type of vulnerability is classified as a stack-based buffer overflow in the context of the ATT&CK framework under the technique T1059.007 for command and scripting interpreter, as successful exploitation typically results in arbitrary code execution that can be used to establish command and control channels or escalate privileges within the compromised system.
The operational impact of CVE-2002-0846 extends beyond simple remote code execution to encompass a broad range of security implications including privilege escalation, system compromise, and potential data exfiltration. Attackers can leverage this vulnerability to deliver malware payloads, establish persistent backdoors, or perform reconnaissance activities against vulnerable systems. The vulnerability affects multiple versions of Macromedia Shockwave Flash player across different operating systems including Windows, macOS, and Linux platforms where Flash support is enabled. Given that Shockwave Flash was widely deployed across enterprise environments and consumer systems during the early 2000s, the potential attack surface for this vulnerability was extensive. The exploitability of this vulnerability is enhanced by the fact that many organizations had Flash plugins enabled by default in their web browsers, making the attack vector particularly effective through web-based delivery methods such as malicious websites, email attachments, or social engineering campaigns.
Mitigation strategies for CVE-2002-0846 primarily involve immediate patching of affected Flash player versions and implementing network-based security controls to prevent access to known malicious SWF content. Organizations should disable Flash plugin support in web browsers where possible and implement web application firewalls that can detect and block malformed SWF file requests. The vulnerability can also be addressed through proper input validation mechanisms and memory protection features such as stack canaries and address space layout randomization. Security professionals should monitor for exploitation attempts through network traffic analysis and implement intrusion detection systems that can identify patterns associated with SWF file header manipulation. Additionally, user education regarding the risks of visiting untrusted websites and opening unknown file attachments remains crucial in preventing successful exploitation attempts, particularly since this vulnerability could be exploited through social engineering campaigns that trick users into visiting malicious websites hosting compromised SWF files.