Attack Chain

1. The attacker identifies a vulnerable UTT HiPER 1200GW device running a firmware version up to 2.5.3-1703.
2. The attacker crafts a malicious HTTP request targeting the /goform/formUser endpoint.
3. The crafted request includes a payload designed to overflow the buffer when processed by the strcpy function.
4. The vulnerable strcpy function in /goform/formUser attempts to copy the overly long input into a fixed-size buffer.
5. The buffer overflow overwrites adjacent memory regions, potentially including return addresses or other critical data.
6. If the attacker successfully overwrites the return address, they can redirect execution to arbitrary code.
7. The attacker injects shellcode into the overflowed buffer or another accessible memory location.
8. The device executes the attacker-controlled shellcode, granting the attacker remote control.

Impact

Successful exploitation of this vulnerability could allow a remote attacker to execute arbitrary code on the UTT HiPER 1200GW device. This could lead to complete system compromise, including data theft, device manipulation, or use of the device as part of a botnet. Given the availability of public exploits, the risk of widespread exploitation is high.

Recommendation

• Apply the Sigma rule Detect UTT HiPER Buffer Overflow Attempt via formUser to detect malicious requests targeting the vulnerable endpoint.
• Apply the Sigma rule Detect Shellcode in HTTP Request to formUser to detect shellcode in HTTP requests to the vulnerable endpoint.
• Monitor web server logs for suspicious activity related to the /goform/formUser endpoint using the webserver log source.
• Apply any available patches or firmware updates provided by UTT to address CVE-2026-7512.