CVE-2011-4256 in RealPlayer
Summary
by MITRE
The RV30 codec in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before 12.0.0.1703 does not initialize an unspecified index value, which allows remote attackers to execute arbitrary code via unknown vectors.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-4256 represents a critical memory corruption flaw within the RV30 codec implementation in RealNetworks RealPlayer software across multiple platforms. This issue affects both Windows and Mac operating systems with specific version ranges where the codec fails to properly initialize an unspecified index value during media processing operations. The root cause lies in inadequate input validation and memory management practices within the video codec handling subsystem, creating a potential exploitation vector for remote attackers seeking to compromise affected systems.
The technical nature of this vulnerability stems from the codec's failure to properly initialize memory structures before processing potentially malicious media content. When the RV30 codec encounters specially crafted media files, the uninitialized index value can lead to unpredictable memory access patterns that may result in stack corruption or heap overflow conditions. This type of flaw typically falls under CWE-457: Use of Uninitialized Variable, which is classified as a fundamental programming error that can lead to arbitrary code execution. The vulnerability's remote exploitation capability suggests that attackers can deliver malicious content through network-based delivery mechanisms without requiring local system access.
From an operational impact perspective, this vulnerability poses significant risks to organizations and individual users who may inadvertently encounter malicious media files while browsing the internet or downloading content. The attack surface is broad as RealPlayer was widely distributed across multiple platforms and used for various multimedia applications. Successful exploitation could allow attackers to execute arbitrary code with the privileges of the affected user, potentially leading to full system compromise, data exfiltration, or establishment of persistent backdoors. The vulnerability's characteristics align with ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell, though the primary attack vector would be through media file delivery rather than traditional PowerShell exploitation.
Mitigation strategies for this vulnerability should focus on immediate software updates to the patched versions of RealPlayer that address the uninitialized variable issue. Organizations should implement network-based controls to block access to potentially malicious media content and deploy endpoint protection solutions that can detect and prevent exploitation attempts. The fix typically involves proper initialization of all variables and indexes before use, implementing bounds checking mechanisms, and conducting thorough input validation for all media processing operations. Additionally, users should be educated about the risks of opening untrusted media files and the importance of keeping software updated to prevent exploitation of known vulnerabilities. Security teams should monitor for indicators of compromise related to this vulnerability and ensure comprehensive patch management processes are in place to address similar memory corruption issues in other multimedia applications.