CVE-2002-1881 in Flash Player
Summary
by MITRE
Macromedia Flash Player 4.0 r12 through 6.0.47.0 allows remote attackers to cause a denial of service (web browser crash) via malformed content in a Flash Shockwave (.SWF) file, as demonstrated by by ROT13 encoding the body of the file but not the headers.
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Analysis
by VulDB Data Team • 07/05/2024
The vulnerability described in CVE-2002-1881 represents a classic denial of service flaw affecting Macromedia Flash Player versions 4.0 r12 through 6.0.47.0. This weakness specifically targets the Flash Player's handling of Shockwave Flash (.SWF) files, which were widely used for multimedia content on web browsers during the early 2000s. The vulnerability arises from insufficient input validation and parsing mechanisms within the Flash Player's interpreter, creating an exploitable condition that can be triggered by malformed SWF content. The attack vector involves remote execution through web-based delivery, where an attacker can craft malicious SWF files designed to crash or freeze web browsers when rendered by the vulnerable Flash Player software.
The technical exploitation of this vulnerability demonstrates a sophisticated understanding of how Flash Player processes file structures and handles data parsing. The specific method described involves ROT13 encoding of the file body while leaving headers unencoded, creating a condition where the Flash Player's parser encounters unexpected data patterns that cause it to fail during content interpretation. This technique exploits the gap between the expected file format structure and the actual data processing logic within the Flash Player's runtime environment. The vulnerability operates at the application layer and can be classified under CWE-129, which encompasses issues related to insufficient validation of length fields in input data, particularly when dealing with binary file formats. The flaw represents a buffer over-read condition where the player attempts to parse encoded data without proper validation of the encoding scheme or data boundaries.
The operational impact of CVE-2002-1881 extends beyond simple browser crashes to potentially disrupt user productivity and web browsing experiences across affected systems. When exploited, this vulnerability can cause complete browser freezes or crashes, forcing users to restart their applications and potentially lose unsaved work. The widespread adoption of Flash Player across various operating systems and web browsers meant that this vulnerability could affect a large user base simultaneously. From an attacker perspective, this represents a low-effort, high-impact method for causing service disruption, aligning with ATT&CK technique T1499.004 for network denial of service attacks. The vulnerability's remote nature means that attackers can exploit it without requiring physical access to target systems, making it particularly dangerous in web-based environments where users expect to encounter trusted content.
Mitigation strategies for CVE-2002-1881 primarily focus on software updates and browser security configurations. The most effective approach involves immediate patching of Flash Player installations to versions that properly validate SWF file structures and implement robust input sanitization. Organizations should implement content filtering mechanisms that can identify and block suspicious SWF files based on known malicious patterns or file characteristics. Browser security policies should include disabling Flash Player plugins for untrusted websites or implementing strict content security policies that prevent execution of potentially malicious embedded content. Additionally, network administrators can deploy intrusion prevention systems that monitor for known attack signatures related to Flash Player vulnerabilities, though such detection capabilities were limited in 2002 due to the nascent state of network security monitoring tools. The vulnerability underscores the importance of proper input validation and the need for robust error handling in multimedia content players, particularly those that process binary formats with complex internal structures.