Remote Stack-Based Buffer Overflow in UTT HiPER 1200GW

A critical stack-based buffer overflow vulnerability (CVE-2026-76003) exists in UTT HiPER 1200GW routers running firmware versions up to 2.5.3-170306. The vulnerability resides in the strcpy function used within the /goform/formGroupConfig endpoint. A remote, authenticated or potentially unauthenticated attacker can exploit this by sending a crafted HTTP request containing an excessively long value for the 'timestart' argument. This manipulation triggers a buffer overflow, which can lead to denial-of-service or remote code execution. Given the public availability of exploit code, organizations deploying these devices in perimeter or internal roles face an immediate risk of compromise.

Attack Chain

1. Attacker performs reconnaissance to identify UTT HiPER 1200GW web management interfaces reachable over the network.
2. Attacker crafts an HTTP POST or GET request directed at the /goform/formGroupConfig endpoint.
3. The request includes a payload within the 'timestart' parameter designed to exceed the allocated stack buffer.
4. The web server process triggers the strcpy function, which fails to perform bounds checking on the 'timestart' input.
5. The overflow overwrites adjacent memory on the stack, including the saved return pointer of the current function.
6. The process execution flow is redirected to an attacker-controlled address contained within the overflowed payload.
7. The attacker executes arbitrary shellcode or malicious commands within the context of the device's web server process.
8. The final objective is full device compromise, allowing for persistent access, traffic interception, or participation in botnet activity.

Impact

Successful exploitation allows for complete compromise of the affected router, resulting in remote code execution with the privileges of the web management interface. This places the network infrastructure at risk of unauthorized access, traffic monitoring, and denial-of-service. Impact is high due to the potential for attackers to pivot into the internal network through the compromised gateway.

Recommendation

• Prioritize the patching of all UTT HiPER 1200GW devices to the latest available firmware version that addresses CVE-2026-76003.
• Restrict access to the web management interface of all networking equipment to trusted internal management subnets only.
• Deploy the webserver detection rule provided below to identify exploitation attempts targeting the identified vulnerable endpoint.
• Monitor network perimeter logs for anomalous HTTP requests directed at the /goform/formGroupConfig path.