CVE-2026-51605 in CP3 V3.0
Summary
by MITRE • 07/09/2026
A stack-based buffer overflow vulnerability in the RTSP service of Tenda CP3 V3.0 (firmware V31.1.9.991) allows an unauthenticated remote attacker to cause a denial of service via a crafted TEARDOWN request.
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Analysis
by VulDB Data Team • 07/09/2026
The vulnerability under examination represents a critical stack-based buffer overflow within the RTSP service of Tenda CP3 V3.0 firmware version V31.1.9.991, classified as CVE-2023-XXXXX. This flaw resides in the handling of TEARDOWN requests within the Real Time Streaming Protocol implementation, which forms part of the broader set of network protocols used for controlling multimedia streaming sessions. The RTSP service typically operates on port 554 and serves as a control interface for streaming media applications, making it a prime target for exploitation by malicious actors seeking to disrupt normal operations.
The technical execution of this vulnerability occurs when an unauthenticated remote attacker crafts a specially designed TEARDOWN request that exceeds the allocated buffer space within the stack memory allocation. This buffer overflow condition arises from insufficient input validation and bounds checking mechanisms implemented within the RTSP service handling code. The flaw manifests as a classic stack-based buffer overflow where the malicious input overwrites adjacent stack memory locations, potentially leading to arbitrary code execution or system crash. According to CWE-121, this vulnerability maps directly to stack-based buffer overflow conditions that occur when insufficient bounds checking allows data to be written beyond allocated buffer boundaries.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with a mechanism to potentially gain unauthorized access to the device's memory space and execute malicious code. When exploited successfully, the overflow can cause the RTSP service to crash or restart repeatedly, resulting in persistent denial of service for legitimate users attempting to establish streaming sessions. The unauthenticated nature of this vulnerability means that any remote attacker can exploit it without requiring prior credentials or network access privileges, making it particularly dangerous in publicly accessible environments.
The attack vector is specifically targeted at the RTSP protocol implementation within the Tenda CP3 V3.0 device, where the TEARDOWN request processing function fails to properly validate the length of incoming data before copying it into fixed-size buffers. This vulnerability aligns with ATT&CK technique T1210 which describes exploitation of remote services through malformed input handling. The attack requires minimal sophistication as it only necessitates sending a crafted TEARDOWN request to the device's RTSP service port, making it an attractive target for automated exploitation tools and script kiddies.
Mitigation strategies should prioritize immediate firmware updates from Tenda to address the underlying buffer overflow condition through proper bounds checking and input validation mechanisms. Network administrators should implement firewall rules to restrict access to RTSP service ports unless absolutely necessary, and consider disabling RTSP services entirely if not required for operations. Additionally, deploying intrusion detection systems capable of monitoring for malformed TEARDOWN requests can provide early warning of exploitation attempts. The recommended remediation approach aligns with the principle of least privilege and defense in depth strategies outlined in cybersecurity frameworks such as NIST SP 800-53, where proper input validation serves as a fundamental control against buffer overflow vulnerabilities. Organizations should also conduct regular vulnerability assessments to identify similar flaws in other network services and ensure that all devices maintain current firmware versions to prevent exploitation of known vulnerabilities.