CVE-2025-15459 Overview
A buffer overflow vulnerability has been identified in UTT 进取 520W router firmware version 1.7.7-180627. The vulnerability exists in the strcpy function within the /goform/formUser endpoint, where improper handling of the passwd1 argument allows an attacker to trigger a buffer overflow condition. This vulnerability can be exploited remotely over the network, potentially leading to device compromise.
Critical Impact
Remote attackers can exploit this buffer overflow to potentially execute arbitrary code or cause denial of service on affected UTT routers. The exploit has been publicly disclosed, increasing the risk of active exploitation.
Affected Products
- UTT 进取 520W firmware version 1.7.7-180627
Discovery Timeline
- 2026-01-05 - CVE-2025-15459 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2025-15459
Vulnerability Analysis
This vulnerability represents a classic buffer overflow condition (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) in embedded router firmware. The affected component processes user authentication data through a web form interface without proper bounds checking on input data.
The vulnerable code path resides in the /goform/formUser handler, which processes user credential submissions. When the passwd1 parameter is submitted with data exceeding the expected buffer size, the strcpy function copies the entire input into a fixed-size buffer without validating the input length, causing adjacent memory to be overwritten.
Buffer overflow vulnerabilities in embedded network devices are particularly dangerous because they often run with elevated privileges and provide network gateway functionality, making them attractive targets for attackers seeking to pivot into internal networks.
Root Cause
The root cause is the use of the unsafe strcpy function to copy user-supplied input (passwd1 parameter) into a fixed-size buffer without first validating the length of the input data. The strcpy function does not perform bounds checking and will continue copying data until it encounters a null terminator, regardless of the destination buffer size.
Attack Vector
The vulnerability is exploitable remotely over the network. An attacker with low privileges (authenticated access) can send a specially crafted HTTP POST request to the /goform/formUser endpoint with an oversized passwd1 parameter value. The network-accessible web management interface makes this vulnerability particularly concerning for internet-exposed devices.
The attack does not require user interaction, allowing attackers to craft automated exploitation attempts. Successful exploitation could result in high impacts to confidentiality, integrity, and availability of the affected device.
Detection Methods for CVE-2025-15459
Indicators of Compromise
- Unusual HTTP POST requests to /goform/formUser with abnormally large passwd1 parameter values
- Router crashes, unexpected reboots, or unresponsive web management interface
- Anomalous outbound network traffic from the router device
- Modified router configuration or unexpected administrative accounts
Detection Strategies
- Monitor HTTP traffic to router management interfaces for requests with unusually long parameter values
- Implement network-based intrusion detection rules to flag oversized POST data to /goform/formUser
- Deploy application-layer firewalls capable of inspecting and limiting parameter sizes in HTTP requests
- Enable logging on network devices and monitor for authentication anomalies
Monitoring Recommendations
- Configure network monitoring to alert on management interface access from unexpected IP ranges
- Implement rate limiting on authentication endpoints to slow exploitation attempts
- Monitor router system logs for crash events or memory-related errors
- Establish baseline behavior for router management traffic patterns to detect anomalies
How to Mitigate CVE-2025-15459
Immediate Actions Required
- Restrict access to the router's web management interface to trusted networks only
- Disable remote management access if not operationally required
- Implement network segmentation to isolate vulnerable devices
- Consider replacing affected devices with actively supported alternatives if no patch is available
Patch Information
The vendor (UTT) was contacted about this vulnerability but did not respond. No official patch is currently available. Organizations should check the VulDB entry for updates on vendor response or refer to the GitHub CVE Documentation for additional technical details.
Workarounds
- Configure firewall rules to restrict access to the management interface (typically port 80/443) from untrusted networks
- Use a VPN for remote administration rather than exposing the management interface directly
- Implement an upstream firewall or web application firewall to filter malicious requests
- Consider network isolation of the affected device behind additional security controls
# Example iptables rules to restrict management interface access
# Allow management access only from trusted admin network
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
