CVE-2026-2070 Overview
CVE-2026-2070 is a buffer overflow vulnerability in the UTT 进取 520W router firmware version 1.7.7-180627. The flaw resides in the strcpy function call within the /goform/formPolicyRouteConf handler. Attackers can manipulate the GroupName argument to overflow a fixed-size buffer, corrupting adjacent memory on the device. The issue is reachable over the network and requires only low-privileged authentication. Public disclosure of the exploit details has occurred, and the vendor did not respond to early notification. The weakness is classified under [CWE-119], improper restriction of operations within the bounds of a memory buffer.
Critical Impact
Remote attackers with low privileges can trigger a buffer overflow in the formPolicyRouteConf handler, compromising confidentiality, integrity, and availability of affected UTT 520W devices.
Affected Products
- UTT 520W Firmware version 1.7.7-180627
- UTT 520W hardware (CPE cpe:2.3:h:utt:520w:3.0)
- Deployments exposing the web management interface (/goform/formPolicyRouteConf)
Discovery Timeline
- 2026-02-06 - CVE-2026-2070 published to NVD
- 2026-02-13 - Last updated in NVD database
Technical Details for CVE-2026-2070
Vulnerability Analysis
The vulnerability exists in the request handler for /goform/formPolicyRouteConf on the UTT 520W router. The handler reads the GroupName parameter from the HTTP request and passes it directly to strcpy without validating the source length. Because strcpy copies bytes until it encounters a null terminator, an oversized GroupName value overflows the destination buffer on the stack or in adjacent memory.
An authenticated attacker can send a crafted HTTP request to the management interface to trigger memory corruption. Successful exploitation can crash the device, alter control flow, or in some scenarios lead to arbitrary code execution on the embedded system. Because the device runs as a network gateway, compromise can pivot into the internal network.
The vendor was notified prior to disclosure but did not respond. No official patch is currently available, and proof-of-concept details have been published in the GitHub CVE Documentation and VulDB entry #344637.
Root Cause
The root cause is the unsafe use of strcpy on user-controlled input. The firmware accepts the GroupName HTTP parameter and copies it into a fixed-size buffer without bounds checking. This pattern, classified as [CWE-119], is common in embedded web interfaces written in C that rely on legacy string functions.
Attack Vector
The attack vector is network-based. An attacker with low-privilege credentials to the router's web management interface sends a POST request to /goform/formPolicyRouteConf with an oversized GroupName field. The request triggers the overflow during request parsing. No user interaction is required beyond the attacker's own request. Devices exposing the management interface to untrusted networks face elevated risk.
No verified exploit code is published in this advisory. Refer to the VulDB CTI entry for technical context.
Detection Methods for CVE-2026-2070
Indicators of Compromise
- HTTP POST requests to /goform/formPolicyRouteConf containing unusually long GroupName parameter values
- Unexpected reboots, watchdog resets, or crash logs on UTT 520W devices following inbound management traffic
- Authenticated sessions originating from unexpected geographies or off-hours administrative access
Detection Strategies
- Inspect web traffic to router management endpoints and alert on GroupName values exceeding expected length thresholds
- Correlate authentication events on the router with subsequent device instability or service restarts
- Apply network IDS signatures that flag oversized form fields targeting /goform/ paths on UTT firmware
Monitoring Recommendations
- Forward router syslog and crash telemetry to a centralized logging platform for anomaly review
- Monitor management-plane access lists for new or unexpected source addresses
- Track configuration changes to policy routing groups for unauthorized modifications
How to Mitigate CVE-2026-2070
Immediate Actions Required
- Restrict access to the UTT 520W web management interface to trusted administrative networks only
- Disable remote (WAN-side) management on the affected devices until a vendor fix is available
- Rotate administrative credentials and enforce strong, unique passwords to reduce low-privilege attacker reach
- Audit policy routing configurations for unauthorized GroupName entries
Patch Information
No vendor patch is available at the time of publication. The vendor did not respond to pre-disclosure outreach, according to the VulDB submission #745264. Organizations should track the UTT vendor site for future firmware updates and consider replacement with supported hardware if the device is end-of-life.
Workarounds
- Place the router management interface behind a VPN or jump host accessible only to administrators
- Apply firewall rules to block inbound HTTP/HTTPS access to the device from untrusted segments
- Implement web application firewall rules upstream to drop requests with oversized GroupName parameters targeting /goform/formPolicyRouteConf
- Plan migration to firmware or hardware with active vendor support if no patch is released
# Example: restrict router management to a trusted subnet using iptables on an upstream gateway
iptables -A FORWARD -p tcp -d <router-ip> --dport 80 \
-s 10.0.0.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d <router-ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router-ip> --dport 443 \
-s 10.0.0.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d <router-ip> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
