CVE-2026-51604 in CP3
Summary
by MITRE • 07/09/2026
A stack-based buffer overflow vulnerability in the RTSP service of Tenda CP3 V3.0 (firmware V31.1.9.91) allows an unauthenticated remote attacker to cause a denial of service via a crafted PLAY request.
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Analysis
by VulDB Data Team • 07/09/2026
The vulnerability under analysis represents a critical stack-based buffer overflow within the RTSP service component of Tenda CP3 V3.0 firmware version V31.1.9.91. This flaw exists in the handling of PLAY requests transmitted through the Real Time Streaming Protocol which is commonly used for controlling media streaming devices. The vulnerability manifests when the device processes a specially crafted PLAY request that exceeds the allocated buffer space on the stack, leading to memory corruption that can result in arbitrary code execution or system instability.
The technical implementation of this vulnerability stems from inadequate input validation within the RTSP service handler routine. When processing incoming PLAY requests, the firmware fails to properly bounds-check the length of data contained in the request parameters before copying them into fixed-size stack buffers. This classic buffer overflow condition occurs because the application assumes that incoming data will not exceed predetermined limits without performing proper validation checks. The CWE-121 classification applies here as the vulnerability involves stack-based buffer overflow due to insufficient bounds checking during data processing. Attackers can exploit this by crafting a malicious PLAY request containing excessive data payload that overflows the designated buffer space, potentially corrupting adjacent memory locations including return addresses and control data.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more sophisticated attacks. While the initial exploitation scenario described focuses on causing denial of service through system crashes or reboots, the underlying buffer overflow condition creates opportunities for remote code execution. An attacker who successfully exploits this vulnerability could gain unauthorized access to the device's operating system and potentially establish persistent control over the network appliance. The attack vector requires no authentication credentials making it particularly dangerous as it can be exploited from any location on the network without prior access privileges. This vulnerability directly maps to ATT&CK technique T1210 - Exploitation of Remote Services, where attackers leverage unauthenticated remote access points to compromise systems.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Tenda to address the buffer overflow condition through proper bounds checking and input validation mechanisms. Network administrators should implement strict firewall rules that block RTSP traffic (port 554) unless absolutely required for legitimate operations, effectively reducing the attack surface exposure. Additionally, deploying network monitoring solutions that can detect anomalous PLAY request patterns or unusually large data payloads may help identify exploitation attempts before they succeed. The implementation of secure coding practices including stack canaries, address space layout randomization, and non-executable stack protections would provide additional layers of defense against exploitation attempts. Organizations should also conduct regular vulnerability assessments of their network infrastructure to identify similar issues in other networked devices that may be running outdated firmware versions with comparable vulnerabilities.