CVE-2025-4755 Overview
CVE-2025-4755 is an improper authentication vulnerability [CWE-287] affecting the D-Link DI-7003GV2 router running firmware version 24.04.18D1 R(68125). The flaw resides in the sub_497DE4 function within the /H5/netconfig.asp endpoint. Attackers can exploit the vulnerability remotely over the network without authentication or user interaction. The exploit details have been publicly disclosed, increasing the likelihood of opportunistic attacks against exposed devices. D-Link classifies the DI-7003GV2 as a business-class gateway, meaning compromised units can expose internal network segments.
Critical Impact
Remote attackers can bypass authentication controls on the network configuration interface, potentially altering router settings and pivoting into connected networks.
Affected Products
- D-Link DI-7003GV2 hardware revision v2
- D-Link DI-7003G firmware version 24.04.18D1 R(68125)
- Deployments exposing the /H5/netconfig.asp management endpoint to untrusted networks
Discovery Timeline
- 2025-05-16 - CVE-2025-4755 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-4755
Vulnerability Analysis
The vulnerability is an improper authentication weakness in the network configuration handler of the DI-7003GV2 web management interface. The sub_497DE4 function processes requests to /H5/netconfig.asp without correctly validating the requester's authentication state. As a result, remote attackers can manipulate request parameters to invoke privileged configuration logic that should be restricted to authenticated administrators.
The attack requires only network reachability to the router's HTTP management service. No credentials, tokens, or user interaction are needed. Because public technical details have been disclosed on GitHub and VulDB, weaponization by opportunistic scanners is realistic. The EPSS model reflects elevated exploitation probability relative to typical embedded device CVEs.
Root Cause
The root cause is missing or insufficient authentication enforcement inside the sub_497DE4 handler. The function fails to verify session validity before executing sensitive configuration operations exposed by netconfig.asp. Embedded web stacks on SOHO and small-business routers frequently rely on ad-hoc session checks that omit specific endpoints, which is consistent with the pattern observed here.
Attack Vector
An attacker sends crafted HTTP requests directly to /H5/netconfig.asp on the target device. If the management interface is reachable from the WAN or an untrusted LAN segment, the request reaches sub_497DE4 and bypasses authentication checks. See the public vulnerability write-up and the VulDB entry #309057 for observed request patterns and parameter details.
Detection Methods for CVE-2025-4755
Indicators of Compromise
- Unauthenticated HTTP or HTTPS requests to /H5/netconfig.asp originating from external or unexpected internal sources
- Unexplained changes to network configuration, DNS, routing, or VPN parameters on the DI-7003GV2
- New administrative sessions or configuration commits without corresponding authenticated logins in device logs
- Outbound traffic to unfamiliar hosts following configuration modifications
Detection Strategies
- Inspect HTTP access logs on the device and any upstream reverse proxy for requests targeting netconfig.asp without a preceding authenticated session
- Compare periodic snapshots of router configuration to baseline exports to identify unauthorized drift
- Alert on management-plane access from IPs outside a defined administrative allow list
Monitoring Recommendations
- Forward router syslog and HTTP access logs into a centralized SIEM or data lake for correlation with network telemetry
- Track new outbound connections from hosts behind the DI-7003GV2 after any configuration change
- Enable network flow monitoring at the WAN edge to detect scanning activity probing /H5/ paths across the estate
How to Mitigate CVE-2025-4755
Immediate Actions Required
- Restrict access to the router's web management interface to trusted administrative subnets using firewall rules or ACLs
- Disable WAN-side administration if it is currently enabled on the DI-7003GV2
- Rotate administrative credentials and audit existing configuration for unauthorized changes
- Isolate the device on a dedicated management VLAN until a vendor patch is applied
Patch Information
At the time of publication no fixed firmware version is listed in the NVD entry or in the referenced advisories. Consult the D-Link official website for firmware updates and security bulletins specific to the DI-7003GV2 hardware revision.
Workarounds
- Block inbound TCP traffic to the router's HTTP and HTTPS management ports from all untrusted networks
- Place the DI-7003GV2 behind an upstream firewall that filters requests to /H5/netconfig.asp
- Where feasible, replace affected units with devices receiving current security updates until a firmware fix is available
# Example ACL restricting management access to a trusted admin subnet
# Adjust interface names and subnets to match the deployment
iptables -A INPUT -p tcp --dport 80 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.10.0.0/24 -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.
