CVE-2011-4257 in RealPlayer
Summary
by MITRE
The Cook codec in RealNetworks RealPlayer before 15.0.0 allows remote attackers to execute arbitrary code via crafted channel data.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-4257 represents a critical buffer overflow flaw within the Cook codec implementation of RealNetworks RealPlayer software. This vulnerability exists in versions prior to 15.0.0 and specifically targets the handling of channel data within the audio decoding process. The Cook codec is a proprietary audio compression format developed by RealNetworks, widely used in media files and streaming applications. When the vulnerable RealPlayer software processes specially crafted channel data, it fails to properly validate input parameters, leading to memory corruption that can be exploited by remote attackers.
The technical exploitation of this vulnerability occurs through a classic buffer overflow attack vector where maliciously constructed channel data exceeds the allocated buffer space within the Cook codec parser. This overflow enables attackers to overwrite adjacent memory locations, potentially including return addresses or function pointers, thereby allowing arbitrary code execution on the target system. The vulnerability is particularly dangerous because it operates remotely without requiring user interaction, making it susceptible to automated exploitation through malicious media files or streaming content. The flaw demonstrates characteristics consistent with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to write beyond allocated memory regions.
From an operational perspective, this vulnerability presents significant risk to users of older RealPlayer versions who may encounter malicious media files or be subjected to drive-by downloads from compromised websites. The impact extends beyond simple code execution to potential system compromise, as successful exploitation could lead to full system control, data exfiltration, or the installation of additional malware. Security researchers have documented this vulnerability as part of the broader category of media player exploits that leverage codec parsing flaws, which aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The vulnerability affects a wide range of systems since RealPlayer was widely distributed and used across multiple platforms, including Windows, macOS, and Linux operating systems.
Mitigation strategies for CVE-2011-4257 primarily focus on immediate software updates to RealPlayer version 15.0.0 or later, which contain patched implementations of the Cook codec with proper input validation. System administrators should also implement network-level protections such as content filtering and media file scanning to prevent potentially malicious files from reaching end users. Additional defensive measures include disabling RealPlayer plugins in web browsers, implementing application whitelisting policies, and monitoring for suspicious network traffic patterns associated with exploitation attempts. Organizations should also consider deploying intrusion detection systems capable of identifying exploitation patterns related to buffer overflow attacks, particularly those targeting multimedia codecs. The vulnerability underscores the importance of keeping media player software updated and highlights the need for robust input validation in multimedia processing components, which aligns with security best practices outlined in NIST SP 800-144 for software security engineering.