A critical stack-based buffer overflow vulnerability in multiple Linksys range extender models poses a severe risk of remote code execution and persistent service denial.

This is a stack-based buffer overflow (CWE-121) occurring within the /goform/RP_pingGatewayByBBS endpoint. An attacker with low-level privileges can supply an overly long string to the ssidhex parameter, which lacks proper bounds checking, allowing them to overwrite the function return address and potentially execute arbitrary code.

Successful exploitation of this vulnerability allows an attacker to achieve full control over the affected range extender device. Given the CVSS score of 8.8, this represents a high-severity risk: attackers could intercept network traffic, pivot into the local network, or cause permanent denial of service. The lack of a vendor-provided patch significantly elevates the impact on operational continuity and network integrity.

Immediate Action: As no official vendor patch is currently available, administrators should immediately isolate these devices from the public-facing internet and restrict administrative access to trusted management subnets only.

Proactive Monitoring: Monitor network traffic for unusual POST requests targeting the /goform/RP_pingGatewayByBBS endpoint, as well as unexpected device reboots or service instability.

Compensating Controls: Deploy a Web Application Firewall or network-based intrusion detection system to block malformed HTTP POST requests containing excessively long ssidhex parameters.

Public Exploit Available: Yes, a proof-of-concept is available via the researcher's technical write-up on GitHub.

Due to the absence of a vendor-supplied update and the public availability of exploit material, this vulnerability poses a significant risk to organizational infrastructure. IT teams must implement immediate network segmentation to isolate these devices and monitor for signs of compromise until the vendor provides a firmware resolution.