A stack-based buffer overflow vulnerability in Tenda M3 firmware version 1.0.0.12 allows authenticated remote attackers to execute arbitrary code or crash the device.

The vulnerability exists in the formGetMasterPassengerAnalyseData function within the /goform/getMasterPassengerAnalyseData endpoint. An authenticated attacker can trigger a stack-based buffer overflow by sending a crafted request containing an overly long time parameter, as the application fails to perform necessary length checks before copying the input into a fixed-size buffer.

Successful exploitation of this vulnerability could lead to a complete compromise of the affected router, potentially granting an attacker persistent access to the network or causing critical service disruption. Given the CVSS score of 8.8, this flaw represents a significant risk to network availability and data confidentiality, especially if the device acts as a gateway for sensitive internal communications.

Immediate Action: Since no official patch is currently available, restrict access to the management interface to trusted administrative IP addresses only and disable remote management features.

Proactive Monitoring: Monitor network traffic and router system logs for repeated POST requests to the /goform/getMasterPassengerAnalyseData endpoint, particularly those containing unusually large strings in the time parameter.

Compensating Controls: Implement a Web Application Firewall or network-level access control list to inspect and drop traffic directed at the vulnerable endpoint from unauthorized sources.

Public Exploit Available: Yes, a published proof-of-concept exists, as documented in the technical write-up provided by the vulnerability researcher.

Given the severity of this vulnerability and the availability of a public proof-of-concept, administrators must prioritize the isolation of affected Tenda M3 devices. Because a vendor patch is currently missing, users should contact the vendor for firmware updates and apply them immediately upon release, while strictly enforcing network access controls to prevent unauthorized exploitation attempts from remote actors.