CVE-2019-25708: CSRF in Heatmiser Wifi Thermostat

The primary impact of CVE-2019-25708 is the potential for unauthorized modification of the Heatmiser Wifi Thermostat's administrative settings. An attacker could leverage this CSRF vulnerability to change the administrator username and password, effectively gaining full control over the device. This could lead to unauthorized access to the thermostat's configuration, potentially allowing manipulation of heating schedules, temperature settings, and other critical functions. The blast radius extends to any user who interacts with the thermostat's web interface while logged in, making them susceptible to the attack. While no direct precedent exists for this specific device, CSRF vulnerabilities are commonly exploited to gain administrative access, similar to scenarios seen in web application attacks.

1. Reserved2026-04-12
2. Published2026-04-12
3. Modified2026-04-13
4. EPSS updated2026-04-20

The primary mitigation for CVE-2019-25708 is to upgrade to a patched version of the Heatmiser Wifi Thermostat firmware. Unfortunately, a fixed version is not explicitly stated in the available information. As a workaround, implementing a Web Application Firewall (WAF) with CSRF protection rules can help prevent malicious requests from being processed. Specifically, WAF rules should be configured to scrutinize requests to the networkSetup.htm endpoint, particularly those containing the usnm, usps, and cfps parameters. Additionally, educating users about the risks of clicking on suspicious links or submitting forms from untrusted sources can reduce the likelihood of exploitation. After applying WAF rules, verify their effectiveness by attempting to submit a crafted CSRF request and confirming it is blocked.