CVE-2011-4252 in RealPlayer
Summary
by MITRE
The RV10 codec in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before 12.0.0.1703 allows remote attackers to execute arbitrary code via a crafted sample height.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-4252 represents a critical buffer overflow flaw within the RV10 codec implementation in RealNetworks RealPlayer software. This security weakness affects both Windows and Mac operating systems, with specific versions impacted including RealPlayer before 15.0.0 and Mac RealPlayer before 12.0.0.1703. The vulnerability stems from inadequate input validation mechanisms within the codec processing pipeline, where the software fails to properly sanitize the sample height parameter in media files. This flaw falls under the CWE-121 buffer overflow category, specifically manifesting as a stack-based buffer overflow due to improper bounds checking during video decoding operations.
The technical exploitation of this vulnerability occurs when a maliciously crafted media file containing an oversized sample height value is processed by the vulnerable RealPlayer application. During the decoding process, the RV10 codec attempts to allocate memory based on the malformed sample height parameter, resulting in a buffer overflow condition that can be leveraged by remote attackers to overwrite adjacent memory locations. This overflow typically occurs in the stack memory region where local variables and return addresses are stored, providing attackers with the opportunity to inject and execute arbitrary code with the privileges of the affected user. The vulnerability is particularly concerning because it can be triggered through automated means via web-based attacks or email attachments without requiring user interaction beyond opening the malicious media file.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to gain complete control over affected systems. Successful exploitation can lead to unauthorized system access, data theft, privilege escalation, and potential persistence mechanisms within the victim environment. This vulnerability directly maps to several ATT&CK tactics including execution through malicious file delivery, privilege escalation via code injection, and persistence through system compromise. The widespread adoption of RealPlayer across various platforms made this vulnerability particularly dangerous, as it could affect numerous users and organizations relying on the software for media playback. The vulnerability's remote exploitability means that attackers could potentially compromise systems without physical access, making it a significant threat vector in enterprise environments where media files are frequently shared and accessed.
Mitigation strategies for CVE-2011-4252 primarily focus on immediate software updates and patches provided by RealNetworks, which address the underlying buffer overflow conditions in the RV10 codec implementation. Organizations should implement network segmentation and access controls to limit exposure to potentially malicious media content, while also deploying content filtering solutions that can detect and block suspicious media files. Security administrators should consider disabling RealPlayer in enterprise environments where it is not strictly required, and implement application whitelisting policies to prevent execution of untrusted media files. Additionally, regular security assessments should be conducted to identify any remaining vulnerable installations, and users should be educated about the risks of opening media files from untrusted sources. The vulnerability serves as a reminder of the importance of proper input validation and memory management in multimedia processing software, highlighting the need for robust software security practices throughout the development lifecycle.