CVE-2025-11355 Overview
CVE-2025-11355 is a buffer overflow vulnerability in the UTT 1250GW router firmware versions up to v2v3.2.2-200710. The flaw resides in the strcpy call within the /goform/aspChangeChannel handler. Attackers can manipulate the pvid argument to overflow a fixed-size stack buffer. The issue is remotely exploitable and a public proof-of-concept has been disclosed. The vendor was contacted prior to public disclosure but did not respond. The weakness is classified under [CWE-119], improper restriction of operations within the bounds of a memory buffer.
Critical Impact
Remote attackers with low-privileged access can corrupt memory on the UTT 1250GW router, potentially leading to arbitrary code execution or device compromise.
Affected Products
- UTT 1250GW router (hardware revision 2.0)
- UTT 1250GW firmware up to v2v3.2.2-200710
- Deployments exposing the web management interface to untrusted networks
Discovery Timeline
- 2025-10-07 - CVE-2025-11355 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2025-11355
Vulnerability Analysis
The UTT 1250GW exposes a web-based administration interface that handles channel change requests through the /goform/aspChangeChannel endpoint. The handler calls strcpy to copy the user-supplied pvid parameter into a fixed-size stack buffer without validating its length. Supplying an oversized value overruns the destination buffer and corrupts adjacent stack memory, including the saved return address.
Successful exploitation can crash the device or redirect execution to attacker-controlled data. On embedded MIPS or ARM routers without modern exploit mitigations, this class of bug commonly enables arbitrary code execution as the web server process.
Root Cause
The root cause is the use of the unbounded strcpy function against attacker-controlled HTTP form input. The aspChangeChannel handler does not enforce a maximum length on the pvid parameter before copying it. No stack canaries, ASLR, or non-executable stack protections are documented for the affected firmware, which amplifies the impact of the boundary violation.
Attack Vector
An attacker reaches the vulnerable endpoint over the network by sending a crafted HTTP request to /goform/aspChangeChannel with an oversized pvid value. The attack requires low-level authenticated access to the management interface. Where the interface is exposed to the WAN, the attack can be conducted from the public internet. Refer to the public proof-of-concept for the exact request structure.
No verified exploitation code is reproduced here. The vulnerability mechanism is straightforward: an HTTP POST containing a pvid field larger than the destination buffer triggers the overflow inside strcpy. See the GitHub CVE Repository and VulDB entry #327240 for technical details.
Detection Methods for CVE-2025-11355
Indicators of Compromise
- HTTP POST requests targeting /goform/aspChangeChannel containing unusually long pvid parameter values
- Repeated router reboots, watchdog resets, or httpd process crashes in device logs
- Unexpected outbound connections originating from the router management plane
- New or modified administrative accounts on the device following suspicious web traffic
Detection Strategies
- Inspect web server access logs on the router for requests to /goform/aspChangeChannel with parameter values exceeding typical VLAN ID lengths
- Deploy network intrusion detection signatures that flag oversized form fields directed at UTT management interfaces
- Correlate router crash events with preceding HTTP traffic to the administrative interface
Monitoring Recommendations
- Forward router syslog and HTTP access logs to a centralized SIEM for retention and correlation
- Alert on any inbound connections to the router management port from external or untrusted segments
- Track firmware version inventory across UTT devices to identify hosts still running v2v3.2.2-200710 or earlier
How to Mitigate CVE-2025-11355
Immediate Actions Required
- Restrict access to the router web management interface to trusted management VLANs only
- Disable WAN-side administrative access on all UTT 1250GW devices
- Enforce strong, unique administrator credentials to limit access to the authenticated endpoint
- Audit recent configuration changes and account lists on potentially exposed devices
Patch Information
As of the last NVD update on 2026-01-08, the vendor has not published a security advisory or firmware update addressing CVE-2025-11355. The original reporter notes that UTT did not respond to disclosure outreach. Operators should monitor the VulDB entry for any future vendor response and consider replacement hardware where long-term support is required.
Workarounds
- Place the router management interface behind a firewall rule that allows only specific administrative source IP addresses
- Use a jump host or VPN to access router administration rather than exposing the interface directly
- Segment the affected devices from sensitive internal networks to limit lateral impact if compromised
- Where feasible, replace end-of-support UTT 1250GW units with actively maintained equipment
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
