CVE-2007-6626 in Feng
Summary
by MITRE
Multiple buffer overflows in the RTSP_valid_response_msg function in RTSP_state_machine.c in LScube Feng 0.1.15 and earlier allow remote attackers to execute arbitrary code via (1) a long first line of a response, as demonstrated by a long VER line; or (2) a long second line of a response, as demonstrated by a message that follows a RETURN line.
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Analysis
by VulDB Data Team • 09/14/2018
The vulnerability identified as CVE-2007-6626 represents a critical buffer overflow issue within the LScube Feng streaming media server version 0.1.15 and earlier. This flaw resides in the RTSP_state_machine.c file within the RTSP_valid_response_msg function, which processes RTSP (Real Time Streaming Protocol) response messages. The vulnerability specifically targets the handling of response message formatting where the server fails to properly validate input lengths before copying data into fixed-size buffers. This design flaw creates exploitable conditions that can be leveraged by remote attackers to execute arbitrary code on the affected system. The vulnerability manifests when processing RTSP response messages that contain excessively long first or second lines, with particular exploitation vectors involving long VER lines in the first line and extended message content following RETURN lines in the second line.
The technical implementation of this vulnerability stems from inadequate input validation and buffer management practices within the RTSP protocol handler. When the RTSP_valid_response_msg function processes incoming response messages, it does not properly check the length of the first line containing the VER (version) information or the second line that follows the RETURN directive. This allows attackers to craft malicious RTSP responses with oversized data payloads that exceed the allocated buffer space. The buffer overflow occurs because the implementation uses unsafe string handling functions that do not perform bounds checking before copying data into fixed-size memory buffers. This creates a classic stack-based buffer overflow condition that can be exploited to overwrite adjacent memory locations including return addresses and function pointers, ultimately enabling remote code execution. The vulnerability aligns with CWE-121, which categorizes stack-based buffer overflows, and CWE-787, which covers out-of-bounds writes that can lead to arbitrary code execution through memory corruption.
The operational impact of this vulnerability extends beyond simple remote code execution, as it represents a significant security risk for streaming media servers that rely on RTSP protocol handling. Attackers can leverage this vulnerability to gain complete control over affected systems, potentially leading to data breaches, service disruption, or further network compromise. The remote nature of the exploit means that attackers do not require local access or authentication to exploit the vulnerability, making it particularly dangerous in networked environments. Systems running LScube Feng versions 0.1.15 and earlier are at risk of being compromised by attackers who can craft specially formatted RTSP responses to trigger the buffer overflow conditions. This vulnerability also aligns with ATT&CK technique T1203, which involves exploiting software vulnerabilities to gain unauthorized access, and T1059, which covers command and scripting interpreter usage for remote code execution. The impact is amplified in environments where streaming media servers are exposed to untrusted networks or where the server handles RTSP responses from multiple sources without proper validation.
Mitigation strategies for CVE-2007-6626 should focus on immediate patching of the LScube Feng software to version 0.1.16 or later, which contains the necessary fixes for the buffer overflow conditions. Organizations should implement network segmentation to limit exposure of affected streaming servers to untrusted networks and consider deploying intrusion detection systems to monitor for suspicious RTSP traffic patterns. Input validation should be strengthened at all protocol handling layers to ensure proper bounds checking on all incoming message components. System administrators should also implement monitoring for unusual memory access patterns and consider implementing address space layout randomization (ASLR) and data execution prevention (DEP) mechanisms to reduce exploit reliability. Additionally, regular security assessments of streaming media infrastructure should be conducted to identify and remediate similar vulnerabilities in other protocol handlers and media streaming applications. The vulnerability demonstrates the importance of secure coding practices and proper input validation in network protocol implementations, particularly for applications handling real-time streaming protocols that may be exposed to external network traffic.