A critical stack-based buffer overflow vulnerability in Tenda FH1202 routers, identified in version 1.2.0.14(408), poses a severe risk of remote code execution.

The vulnerability exists in the formWrlsafeset function within the /goform/AdvSetWrlsafeset endpoint, where the mit_ssid argument is processed without sufficient length validation. An authenticated attacker can trigger a stack-based buffer overflow, leading to memory corruption.

Successful exploitation of this vulnerability allows an attacker to execute arbitrary code with system-level privileges or cause a complete denial of service. Given the CVSS score of 8.8, this represents a high-severity risk to network availability and data confidentiality. Compromise of the router could facilitate further lateral movement within the network or interception of sensitive traffic.

Immediate Action: Users should immediately check the Tenda support website for firmware updates addressing this buffer overflow and apply them as soon as possible.

Proactive Monitoring: Security teams should monitor network traffic for anomalous POST requests directed at the /goform/AdvSetWrlsafeset endpoint and review device logs for signs of repeated crashes or unauthorized configuration changes.

Compensating Controls: If a patch is unavailable, restrict management interface access to trusted internal IP addresses and employ a Web Application Firewall or network filter to block requests containing excessively long strings in the mit_ssid parameter.

Public Exploit Available: Yes, a published proof-of-concept exists and is attributed to the technical write-up provided in the CVE references.

The presence of a functional proof-of-concept necessitates immediate attention to this vulnerability. Organizations utilizing the Tenda FH1202 router should prioritize updating the firmware to the latest available version to eliminate the buffer overflow risk. If immediate patching is not feasible, strict network segmentation and access control lists must be applied to the administrative interface to prevent unauthorized access.