CVE-2026-76004 Overview
CVE-2026-76004 is a stack-based buffer overflow vulnerability affecting UTT HiPER 1250GW routers running firmware versions up to 3.2.7-210907-180535. The flaw resides in the strcpy call within the /goform/aspApBasicConfigUrcp endpoint of the HTTP Handler component. Attackers can manipulate the pvid argument to overflow the fixed-size stack buffer. The vulnerability is exploitable remotely over the network and requires low-level privileges. Public disclosure of the exploit details has occurred, increasing the risk of active exploitation against exposed devices. The weakness is classified under [CWE-119] for improper restriction of operations within memory buffer bounds.
Critical Impact
Remote attackers with low-privilege access can trigger a stack-based buffer overflow via the pvid HTTP parameter, potentially leading to arbitrary code execution or denial of service on affected UTT HiPER 1250GW devices.
Affected Products
- UTT HiPER 1250GW router
- Firmware versions up to and including 3.2.7-210907-180535
- HTTP Handler component (/goform/aspApBasicConfigUrcp endpoint)
Discovery Timeline
- 2026-08-19 - CVE-2026-76004 published to NVD
- 2026-08-20 - Last updated in NVD database
Technical Details for CVE-2026-76004
Vulnerability Analysis
The vulnerability exists in the HTTP request handler that processes requests to /goform/aspApBasicConfigUrcp on UTT HiPER 1250GW devices. The handler uses the unsafe strcpy function to copy the user-supplied pvid argument into a fixed-size stack buffer without validating its length. Attackers can supply an oversized pvid value to overwrite adjacent stack memory, including saved return addresses and function pointers. Because the router exposes this endpoint over HTTP, exploitation can be triggered remotely against any reachable management interface. Successful exploitation can compromise the confidentiality, integrity, and availability of the device, and by extension the network segment it services. Public availability of the exploit details lowers the barrier for opportunistic attacks against exposed devices.
Root Cause
The root cause is unsafe use of the strcpy function without prior bounds checking on attacker-controlled input. The pvid argument, received as part of the HTTP request body or query string, is copied directly into a stack buffer whose size is smaller than the maximum length of untrusted input. This coding pattern maps to [CWE-119], improper restriction of operations within the bounds of a memory buffer.
Attack Vector
Exploitation occurs over the network by sending a crafted HTTP request to the /goform/aspApBasicConfigUrcp endpoint with an oversized pvid parameter. The attack requires low-level privileges but no user interaction. Attackers targeting internet-exposed management interfaces can trigger the overflow to crash the HTTP service or achieve code execution in the context of the router firmware. Technical details are documented in the GitHub CVE Guide and the VulDB CVE Entry.
Detection Methods for CVE-2026-76004
Indicators of Compromise
- HTTP POST or GET requests to /goform/aspApBasicConfigUrcp containing abnormally long pvid parameter values
- Unexpected reboots, HTTP service crashes, or web management interface unavailability on UTT HiPER 1250GW devices
- Outbound connections from the router to unknown hosts following inbound requests to the affected endpoint
Detection Strategies
- Deploy network intrusion detection signatures that flag requests to /goform/aspApBasicConfigUrcp where the pvid field exceeds expected VLAN identifier lengths
- Correlate router syslog messages showing HTTP handler faults with inbound HTTP traffic to the management interface
- Baseline HTTP request patterns to the router administrative endpoints and alert on deviations
Monitoring Recommendations
- Forward router logs to a centralized log platform and alert on process crashes or watchdog resets
- Monitor for scanning activity targeting /goform/ URI patterns commonly found in SOHO router web interfaces
- Track authentication events on the management interface to detect low-privilege credential abuse preceding exploitation
How to Mitigate CVE-2026-76004
Immediate Actions Required
- Restrict access to the UTT HiPER 1250GW web management interface to trusted internal networks only, blocking WAN-side administration
- Rotate credentials on affected devices, since the attack requires low-privilege authenticated access
- Inventory all UTT HiPER 1250GW devices and identify any running firmware 3.2.7-210907-180535 or earlier
Patch Information
No vendor patch has been referenced in the published advisories at this time. Organizations should monitor UTT's vendor channels for firmware updates addressing the strcpy call in the /goform/aspApBasicConfigUrcp handler. Refer to the VulDB Vulnerability entry for updates on remediation status.
Workarounds
- Disable remote HTTP administration on the WAN interface and restrict management to a dedicated VLAN
- Place affected routers behind an upstream firewall that filters HTTP requests to /goform/aspApBasicConfigUrcp from untrusted sources
- Consider replacing end-of-support UTT HiPER 1250GW devices if no vendor-supplied firmware fix becomes available
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
