CVE-2011-4248 in RealPlayer
Summary
by MITRE
RealNetworks RealPlayer before 15.0.0 allows remote attackers to execute arbitrary code via a malformed AAC file.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-4248 represents a critical remote code execution flaw within RealNetworks RealPlayer software versions prior to 15.0.0. This security issue stems from insufficient input validation and improper handling of malformed audio files, specifically those containing Advanced Audio Coding format data. The flaw exists in the media processing component of RealPlayer that is responsible for parsing and interpreting AAC audio files, creating a pathway for malicious actors to inject and execute arbitrary code on vulnerable systems. The vulnerability demonstrates characteristics consistent with buffer overflow conditions and memory corruption issues commonly found in multimedia processing libraries.
The technical implementation of this vulnerability involves the improper parsing of AAC file structures where the application fails to properly validate the length and format of audio data segments. When a specially crafted malformed AAC file is processed by the vulnerable RealPlayer version, the application's parser encounters unexpected data structures that cause memory corruption. This memory corruption leads to the execution of malicious code placed within the malformed file, effectively allowing remote attackers to gain unauthorized control over the target system. The flaw operates at the application layer and requires no special privileges to exploit, making it particularly dangerous for widespread deployment. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation in multimedia processing applications.
From an operational perspective, this vulnerability presents significant risk to organizations and individual users who rely on RealPlayer for audio playback. Attackers can leverage this flaw through various delivery mechanisms including email attachments, malicious websites, or peer-to-peer file sharing networks. The remote execution capability means that exploitation can occur without user interaction beyond opening the malicious file, making it particularly dangerous for automated attacks. The vulnerability affects a broad user base since RealPlayer was widely distributed across multiple operating systems including windows, macos, and linux platforms. Security analysts have noted that this vulnerability can be weaponized to deliver malware payloads, establish backdoors, or perform other malicious activities that compromise system integrity and user data confidentiality. The exploitability factor is high due to the ease with which malformed files can be distributed and the lack of user awareness required for successful exploitation.
Mitigation strategies for CVE-2011-4248 primarily focus on immediate software updates and system hardening measures. Organizations should prioritize patching all affected RealPlayer installations to version 15.0.0 or later, which contains the necessary fixes for the AAC parsing vulnerability. Network administrators should implement strict file validation policies and consider blocking suspicious audio file types at network boundaries. The use of sandboxing techniques and application whitelisting can provide additional defense layers against exploitation attempts. Security monitoring should include detection of unusual network traffic patterns associated with media file transfers and potential exploitation attempts. System administrators should also consider disabling RealPlayer or similar media players when not actively needed, as well as implementing regular security audits to identify and remediate other potential vulnerabilities in the media processing pipeline. This vulnerability demonstrates the importance of maintaining up-to-date multimedia software and following secure coding practices that validate all external input data. The incident highlights the need for robust input validation and memory safety mechanisms in multimedia applications, aligning with ATT&CK technique T1059.007 for command and scripting interpreter usage.