CVE-2013-4980 in AVN801 DVR
Summary
by MITRE
Buffer overflow in the RTSP Packet Handler in AVTECH AVN801 DVR with firmware 1017-1003-1009-1003 and earlier, and possibly other devices, allows remote attackers to cause a denial of service (device crash) and possibly execute arbitrary code via a long string in the URI in an RTSP SETUP request.
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Analysis
by VulDB Data Team • 07/19/2024
The vulnerability identified as CVE-2013-4980 represents a critical buffer overflow flaw within the RTSP packet handling mechanism of AVTECH AVN801 digital video recorders. This issue affects firmware versions 1017-1003-1009-1003 and earlier, with potential implications for similar devices from the same manufacturer. The vulnerability exists in the way the device processes RTSP SETUP requests, specifically when handling URI parameters that contain excessively long strings. The flaw allows remote attackers to exploit this weakness without requiring authentication, making it particularly dangerous in networked environments where these devices are accessible to untrusted parties. The RTSP protocol serves as a standard communication protocol for controlling multimedia streaming devices, and its implementation in this DVR system creates a pathway for malicious actors to manipulate device behavior through crafted network requests.
The technical implementation of this vulnerability stems from inadequate input validation within the RTSP packet handler component of the DVR firmware. When an RTSP SETUP request is received with an overly long URI string, the device fails to properly bounds-check the input data before copying it into a fixed-size buffer. This classic buffer overflow condition occurs because the system does not verify that the incoming data length exceeds the allocated buffer capacity, leading to memory corruption. The overflow can overwrite adjacent memory locations including return addresses, function pointers, or other critical control data structures within the device's execution environment. According to CWE classification, this represents a CWE-121: Stack-based Buffer Overflow, which falls under the broader category of memory safety vulnerabilities that have been consistently identified as high-risk threats in cybersecurity assessments. The attack vector is particularly concerning as it operates over the network without requiring any form of authentication, aligning with ATT&CK technique T1210: Exploitation of Remote Services.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution on affected devices. When exploited successfully, the buffer overflow can cause the DVR system to crash and restart, resulting in complete service disruption for surveillance operations. However, in more sophisticated attack scenarios, the memory corruption could be leveraged to inject and execute malicious code within the device's operating environment, potentially providing attackers with full administrative control over the surveillance system. This compromise could lead to unauthorized access to recorded video feeds, modification of surveillance data, or even the use of the compromised device as a pivot point for attacking other systems within the same network infrastructure. The implications are particularly severe for security-sensitive environments where these DVR systems are deployed for monitoring critical assets or facilities, as the vulnerability could be exploited to disable security monitoring capabilities entirely.
Mitigation strategies for CVE-2013-4980 should prioritize immediate firmware updates from AVTECH to address the buffer overflow condition. Organizations should implement network segmentation to isolate these devices from untrusted networks and restrict access to RTSP ports to authorized personnel only. Network access control lists and firewall rules should be configured to limit RTSP traffic to specific IP addresses or ranges, reducing the attack surface available to potential exploiters. Additionally, monitoring network traffic for unusual RTSP SETUP requests containing excessively long URI parameters can serve as an early detection mechanism for attempted exploitation. Security professionals should consider implementing intrusion detection systems that can identify patterns consistent with this vulnerability. The vulnerability also underscores the importance of regular security assessments and vulnerability scanning of networked devices, particularly those running legacy firmware versions. Organizations should establish processes for maintaining current firmware versions and regularly reviewing device configurations to ensure that unnecessary services remain disabled. This vulnerability exemplifies why organizations must maintain comprehensive asset inventories and implement robust patch management procedures to protect against known vulnerabilities in embedded systems and networked security devices.