CVE-2005-1766 in RealPlayer
Summary
by MITRE
Heap-based buffer overflow in rtffplin.cpp in RealPlayer 10.5 6.0.12.1056 on Windows, and 10, 10.0.1.436, and other versions before 10.0.5 on Linux, allows remote attackers to execute arbitrary code via a RealMedia file with a long RealText string, such as an SMIL file.
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Analysis
by VulDB Data Team • 06/30/2025
This vulnerability represents a critical heap-based buffer overflow flaw in RealPlayer's RealText parsing functionality that affects multiple platform versions of the media player. The vulnerability specifically resides in the rtffplin.cpp source file where the application fails to properly validate the length of RealText strings contained within RealMedia files, particularly SMIL files that contain embedded RealText content. When a maliciously crafted RealMedia file with an excessively long RealText string is processed by the vulnerable RealPlayer versions, the application attempts to allocate memory on the heap to store this string without adequate bounds checking, leading to memory corruption that can be exploited by remote attackers.
The technical implementation of this vulnerability demonstrates a classic heap overflow condition where the buffer allocation does not account for the actual length of input data, creating a situation where data written to the heap buffer overflows into adjacent memory regions. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses heap-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent heap memory. The flaw is particularly dangerous because it operates within the context of media file parsing, making it accessible through standard file delivery mechanisms without requiring special privileges or user interaction beyond opening the malicious file.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with complete system compromise capabilities through the exploitation of the heap overflow. Attackers can craft malicious SMIL files containing oversized RealText strings that, when processed by vulnerable RealPlayer installations, trigger the buffer overflow condition and allow arbitrary code execution with the privileges of the user running the application. This represents a significant threat vector in enterprise environments where media files are frequently shared and opened by users, potentially enabling attackers to establish persistent access to systems, escalate privileges, or deploy additional malware components. The vulnerability affects both Windows and Linux platforms, expanding the potential attack surface and making it particularly concerning for heterogeneous network environments.
Mitigation strategies for this vulnerability should focus on immediate patching of affected RealPlayer versions, with the recommended approach being the installation of RealPlayer 10.0.5 or later releases that contain the necessary memory validation fixes. System administrators should implement network-level controls to block or scan RealMedia files and SMIL files before they reach end-user systems, particularly in environments where such files are commonly encountered. The vulnerability also highlights the importance of input validation and secure coding practices, with organizations needing to ensure that all applications properly validate input lengths and implement proper bounds checking before memory allocation occurs. Additionally, user education regarding the dangers of opening untrusted media files and the implementation of application whitelisting policies can provide additional layers of defense against exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving execution through fileless means and privilege escalation through code injection, making it a significant concern for organizations implementing comprehensive security controls.