Stack-Based Buffer Overflow in UTT HiPER 1250GW

A critical stack-based buffer overflow vulnerability, tracked as CVE-2026-76004, has been identified in UTT HiPER 1250GW routers running firmware versions up to 3.2.7-210907-180535. The vulnerability resides in the HTTP Handler component, specifically within the strcpy function of the /goform/aspApBasicConfigUrcp file. By submitting a malicious payload via the pvid argument, an authenticated remote attacker can cause a stack-based buffer overflow. This vulnerability has been disclosed publicly, and exploit code is available, increasing the risk of exploitation. Successful exploitation may allow an attacker to gain arbitrary code execution, leading to full system compromise of the network device.

Attack Chain

1. The attacker performs reconnaissance to identify UTT HiPER 1250GW devices exposed to the internet.
2. The attacker establishes an authenticated session with the target device's web management interface.
3. The attacker crafts a malicious HTTP request targeting the /goform/aspApBasicConfigUrcp endpoint.
4. The attacker injects an oversized payload into the pvid argument within the HTTP request.
5. The vulnerable strcpy function in the HTTP handler improperly validates the length of the pvid argument.
6. The overflow overwrites adjacent memory on the stack, allowing for the redirection of execution flow.
7. The attacker executes arbitrary shellcode to gain control of the device or trigger a denial-of-service condition.

Impact

Successful exploitation of CVE-2026-76004 results in a critical security compromise of the affected UTT HiPER 1250GW router. As the device functions as a network gateway, an attacker could intercept or manipulate sensitive internal network traffic, launch further attacks against internal hosts, or render the gateway inoperable, impacting network availability for the entire organization.

Recommendation

• Immediately audit network perimeters for exposed UTT HiPER 1250GW management interfaces and restrict access to authorized management networks only.
• Prioritize updating firmware on all HiPER 1250GW units to a version beyond 3.2.7-210907-180535 as soon as an official vendor patch is released.
• Implement web application firewall (WAF) or intrusion detection system (IDS) rules to monitor for unusually long HTTP POST parameters targeting the /goform/aspApBasicConfigUrcp URI.
• Monitor logs for repeated authentication attempts followed by suspicious request patterns to the management interface.