UTT HiPER 1250GW strcpy Buffer Overflow Vulnerability (CVE-2026-4862)

CVE-2026-4862 describes a critical buffer overflow vulnerability affecting UTT HiPER 1250GW devices up to version 3.2.7-210907-180535. The vulnerability resides in the /goform/formConfigDnsFilterGlobal component's Parameter Handler, specifically within the strcpy function. A remote attacker can exploit this vulnerability by manipulating the GroupName argument, leading to a buffer overflow condition. Successful exploitation could allow an attacker to execute arbitrary code on the affected device. This vulnerability is considered critical due to the ease of remote exploitation and the potential for complete system compromise. The existence of a publicly disclosed exploit increases the likelihood of active exploitation.

Attack Chain

1. The attacker identifies a vulnerable UTT HiPER 1250GW device with a version up to 3.2.7-210907-180535 exposed to the internet.
2. The attacker crafts a malicious HTTP request targeting the /goform/formConfigDnsFilterGlobal endpoint.
3. Within the HTTP request, the attacker includes a GroupName argument with a value exceeding the buffer's expected size.
4. The vulnerable strcpy function in the Parameter Handler attempts to copy the oversized GroupName value into a fixed-size buffer.
5. The buffer overflow occurs, overwriting adjacent memory regions on the stack or heap.
6. The attacker carefully crafts the overflow to overwrite critical data, such as return addresses or function pointers.
7. When the vulnerable function returns, control is redirected to the attacker's injected code.
8. The attacker executes arbitrary code on the UTT HiPER 1250GW device, potentially gaining full control of the system.

Impact

Successful exploitation of CVE-2026-4862 can lead to complete compromise of the UTT HiPER 1250GW device. This can result in disruption of network services, data theft, and the potential for the device to be used as a botnet node. Given the widespread use of these devices in various network environments, a large-scale exploitation could have significant consequences. Affected sectors include small to medium sized businesses who may rely on these devices for critical network functionality.

Recommendation

• Apply available patches or firmware updates for UTT HiPER 1250GW devices to address CVE-2026-4862.
• Monitor web server logs for requests targeting the /goform/formConfigDnsFilterGlobal endpoint with unusually long GroupName parameters to detect potential exploitation attempts (see Sigma rule below).
• Implement network segmentation to limit the impact of a compromised device on other critical systems.
• Deploy the Sigma rules to your web server logs and SIEM to detect exploitation attempts.