CVE-2025-9379 Overview
CVE-2025-9379 affects the Belkin AX1800 router running firmware version 1.1.00.016. The vulnerability resides in the Firmware Update Handler component and stems from insufficient verification of data authenticity [CWE-345]. An attacker can exploit this weakness remotely over the network to deliver unauthenticated firmware to the device. The vendor was contacted before public disclosure but did not respond. Successful exploitation can compromise the confidentiality, integrity, and availability of the affected router and any traffic traversing it.
Critical Impact
Remote attackers with valid privileges can deliver unverified firmware to Belkin AX1800 routers, enabling persistent device compromise and full control of network traffic.
Affected Products
- Belkin AX1800 router, firmware 1.1.00.016
- Firmware Update Handler component on the affected device
- Deployments exposing the router management interface to untrusted networks
Discovery Timeline
- 2025-08-24 - CVE-2025-9379 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-9379
Vulnerability Analysis
The Belkin AX1800 Firmware Update Handler accepts firmware images without sufficient cryptographic verification of their origin or integrity. The device does not enforce a trust check that binds firmware artifacts to a vendor-controlled signing key. As a result, an attacker who can reach the update interface can supply a crafted firmware image that the device treats as authentic. Once installed, modified firmware runs with full device privileges and survives reboots. This places the attacker between the local network and the internet, exposing all routed traffic to interception and manipulation.
Root Cause
The root cause is improper authenticity verification of firmware data, classified under [CWE-345]. The update path lacks an enforced digital signature check, or the existing check can be bypassed because it does not validate the issuer and image hash against a trusted root. Without a verified chain of trust, the router cannot distinguish vendor-signed firmware from attacker-supplied images.
Attack Vector
The attack vector is network-based and requires high privileges on the management interface, according to the published CVSS metrics. An authenticated attacker submits a malicious firmware image through the update handler. The device installs the image without validating its signature, granting the attacker code execution as the firmware runs. User interaction is not required, and the attack does not depend on local access to the router.
No verified public proof-of-concept code is available. Refer to the GitHub Firmware Update Guide and VulDB entry #321212 for additional technical context.
Detection Methods for CVE-2025-9379
Indicators of Compromise
- Unexpected firmware version strings or build identifiers reported by the AX1800 web interface or SNMP
- Outbound connections from the router to unfamiliar hosts shortly after a firmware update event
- DNS responses from the router that diverge from configured upstream resolvers, suggesting tampered firmware
- Configuration changes, new administrative accounts, or altered port forwarding rules with no operator action
Detection Strategies
- Baseline firmware versions and image hashes across the AX1800 fleet, then alert on any deviation
- Monitor administrative authentication events to the router for anomalous source addresses or off-hours activity
- Inspect network telemetry for traffic patterns consistent with a compromised gateway, such as DNS hijacking or TLS interception
Monitoring Recommendations
- Forward router syslog and authentication logs to a centralized analytics platform for retention and correlation
- Track firmware update API calls and flag any update not initiated by an approved change ticket
- Correlate LAN-side device behavior with router event logs to identify downstream impact of a compromised gateway
How to Mitigate CVE-2025-9379
Immediate Actions Required
- Restrict access to the AX1800 management interface to trusted administrative networks only and disable remote WAN administration
- Rotate all administrative credentials on the device, including any shared service accounts used for management
- Audit the running firmware version against the vendor baseline and reimage any device that cannot be verified
Patch Information
At the time of publication, the vendor had not responded to disclosure attempts and no fixed firmware version is referenced in the advisory. Track the VulDB entry and Belkin support channels for updated firmware releases addressing CVE-2025-9379.
Workarounds
- Place the AX1800 behind a segmented management VLAN that blocks untrusted hosts from reaching the update handler
- Enforce strong, unique administrator passwords and disable any unused remote management protocols such as HTTP, Telnet, or UPnP
- Replace the device with a supported router model if the vendor does not provide a signed firmware fix within an acceptable risk window
# Example: block external access to the router management interface at an upstream firewall
iptables -A FORWARD -d 192.0.2.10 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.0.2.10 -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.
