CVE-2005-3900 in Flash Player
Summary
by MITRE
Macromedia Breeze Communication Server and Breeze Live Server does 5.1 and earlier not sufficiently validate certain RTMP data, which allows attackers to cause a denial of service (instability or crash), as demonstrated using an alpha release build of Flash Player 8.5 (build 133).
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Analysis
by VulDB Data Team • 07/29/2017
The vulnerability identified as CVE-2005-3900 affects Macromedia Breeze Communication Server and Breeze Live Server versions 5.1 and earlier, representing a critical flaw in real-time messaging protocol data validation mechanisms. This issue stems from insufficient input validation of RTMP (Real-Time Messaging Protocol) data packets that these servers process, creating a pathway for malicious actors to exploit the system's handling of malformed or unexpected data sequences. The vulnerability specifically targets the server's ability to process RTMP messages without proper sanitization, allowing attackers to craft specially crafted data that can disrupt normal server operations.
The technical exploitation of this vulnerability demonstrates a classic buffer overflow or memory corruption attack pattern that leverages the servers' failure to validate incoming RTMP data structures. When the affected servers receive malformed RTMP packets, particularly those generated by the alpha release build of Flash Player 8.5, the communication server's processing routines encounter unexpected data formats that trigger memory corruption or resource exhaustion conditions. This type of vulnerability aligns with CWE-122, which describes buffer overflow conditions, and CWE-125, which covers out-of-bounds read vulnerabilities, both of which are common in protocols that handle variable-length data streams without proper bounds checking.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire communication infrastructure that relies on these servers. Attackers can leverage this weakness to cause instability or complete crashes of the Breeze servers, resulting in denial of service conditions that affect legitimate users and applications dependent on real-time communication services. The demonstration using Flash Player 8.5 build 133 shows that this vulnerability can be exploited through legitimate client software, making it particularly dangerous as it can be triggered by normal user interactions rather than requiring specialized attack tools or privileged access. This characteristic places the vulnerability in the ATT&CK framework under the T1498 technique category, which covers Network Denial of Service, and potentially T1595 for the use of client-side exploits to target server infrastructure.
Organizations utilizing these legacy systems should implement immediate mitigations including network segmentation to isolate affected servers, implementing strict RTMP data filtering rules, and deploying intrusion detection systems that can identify and block suspicious RTMP traffic patterns. The most effective long-term solution involves upgrading to supported versions of the software that have proper input validation mechanisms and robust error handling for RTMP protocol data. Additionally, administrators should consider implementing rate limiting and connection monitoring to detect anomalous behavior that might indicate exploitation attempts, while maintaining detailed logging of RTMP traffic for forensic analysis and threat hunting activities.