CVE-2001-0166 in Shockwave Flash Plugin
Summary
by MITRE
Macromedia Shockwave Flash plugin version 8 and earlier allows remote attackers to cause a denial of service via malformed tag length specifiers in a SWF file.
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Analysis
by VulDB Data Team • 04/07/2019
The vulnerability identified as CVE-2001-0166 represents a critical denial of service flaw within Macromedia Shockwave Flash plugin versions 8 and earlier. This issue specifically targets the plugin's handling of SWF file structures, where malformed tag length specifiers can trigger unexpected behavior in the flash player's parsing mechanism. The vulnerability resides in the fundamental way the plugin processes file headers and tag structures, creating a scenario where maliciously crafted SWF content can cause the application to crash or become unresponsive.
The technical flaw manifests when the Flash plugin encounters SWF files containing incorrect or corrupted tag length specifications within the file's header structure. These malformed specifiers cause the plugin to misinterpret the file boundaries and tag sizes, leading to buffer overflows or memory corruption during parsing operations. The vulnerability operates at the parser level where the plugin's internal mechanisms for reading and interpreting SWF file formats fail to properly validate the length fields associated with each tag. This weakness falls under the CWE-125 vulnerability category, which encompasses out-of-bounds read conditions that can result in memory corruption and system instability.
From an operational perspective, this vulnerability poses significant risks to end-user systems as it can be exploited through web browsers that have the Flash plugin installed. Attackers can craft malicious SWF files that, when loaded by an affected browser, will cause the Flash plugin to crash, resulting in a denial of service condition for the user. The impact extends beyond simple browser crashes as the exploitation can potentially lead to complete application hangs or system instability, particularly when users visit compromised websites or download malicious content. The vulnerability affects a wide range of systems since Flash was widely distributed and integrated into numerous web browsers and applications during the early 2000s.
The exploitation of this vulnerability aligns with ATT&CK technique T1203, which involves legitimate programs being used for code execution or system manipulation. Security practitioners should consider this vulnerability as part of broader defensive strategies against browser-based attacks and consider implementing content filtering solutions to block potentially malicious SWF files. The remediation approach requires immediate patching of affected Flash plugin versions, with organizations needing to ensure all users have updated to versions that properly validate tag length specifiers. Additionally, network administrators should consider implementing web application firewalls and content inspection systems to prevent delivery of malicious SWF content to vulnerable systems. The vulnerability demonstrates the importance of proper input validation in multimedia processing components and highlights how seemingly benign file format parsing can become a critical security concern when proper validation mechanisms are absent.