CVE-2011-4254 in RealPlayer
Summary
by MITRE
RealNetworks RealPlayer before 15.0.0 allows remote attackers to execute arbitrary code via a crafted RTSP SETUP request.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-4254 represents a critical remote code execution flaw within RealNetworks RealPlayer software version 15.0.0 and earlier. This vulnerability specifically targets the RTSP (Real Time Streaming Protocol) implementation within the media player, creating an avenue for malicious actors to remotely compromise systems through specially crafted SETUP requests. The flaw exists in the handling of RTSP protocol commands, particularly during the initial setup phase of media streaming sessions, where insufficient input validation allows attackers to inject malicious code that executes with the privileges of the running RealPlayer process.
The technical implementation of this vulnerability stems from improper bounds checking and memory management within the RTSP parser component of RealPlayer. When processing a crafted RTSP SETUP request, the application fails to properly validate the length and content of incoming data fields, particularly those related to session identifiers and transport parameters. This inadequate validation creates a buffer overflow condition that can be exploited to overwrite critical memory locations and ultimately redirect program execution flow to attacker-controlled code. The vulnerability aligns with CWE-121, which describes buffer overflow conditions where insufficient bounds checking allows memory corruption. The flaw demonstrates characteristics of a classic stack-based buffer overflow, where attacker-supplied data exceeds the allocated buffer space and corrupts adjacent memory regions including return addresses and function pointers.
From an operational perspective, this vulnerability presents a significant threat to enterprise and individual users alike, as it enables remote code execution without requiring user interaction beyond the normal operation of the media player. Attackers can exploit this weakness by constructing malicious RTSP streams that, when processed by an unpatched RealPlayer client, result in arbitrary code execution on the target system. The implications extend beyond simple exploitation, as the vulnerability can be leveraged to establish persistent backdoors, escalate privileges, or deploy additional malware payloads. The attack surface is particularly concerning given that RealPlayer was widely distributed across various platforms and used for multimedia content delivery, making the potential impact of this vulnerability extensive. This type of vulnerability is classified under the MITRE ATT&CK framework as part of the T1203 technique category, which encompasses the exploitation of software vulnerabilities for code execution, and aligns with T1059 for command and scripting interpreter usage in post-exploitation activities.
Mitigation strategies for CVE-2011-4254 should focus on immediate patch deployment, as RealNetworks released version 15.0.0 to address this specific vulnerability. Organizations should implement network segmentation to limit access to RTSP services and consider deploying network intrusion detection systems to monitor for suspicious RTSP traffic patterns. Additionally, user education regarding the risks of opening untrusted media content and the importance of keeping software updated remains crucial. System administrators should also consider implementing application whitelisting policies that restrict execution of RealPlayer to trusted environments only. The vulnerability highlights the importance of secure coding practices, particularly in protocol implementations where input validation is critical to preventing memory corruption attacks. Organizations should conduct regular vulnerability assessments targeting media player software and streaming protocols to identify similar weaknesses in their infrastructure, as this vulnerability demonstrates how seemingly benign protocol handling can create significant security risks.