CVE-2025-52692 Overview
CVE-2025-52692 is an authentication bypass vulnerability in the Linksys E9450-SG router firmware. An attacker with local network access can send a specially crafted URL to reach administrative functions without supplying valid login credentials. The flaw is classified as Missing Authentication for Critical Function [CWE-306] and affects firmware version 1.2.00.052. Successful exploitation grants the attacker the ability to invoke privileged router functionality reserved for administrators, exposing the device to configuration tampering, traffic interception, and persistent network compromise.
Critical Impact
An adjacent-network attacker can access administrative functions of the Linksys E9450-SG without credentials, enabling full control over the router and downstream network traffic.
Affected Products
- Linksys E9450-SG router (hardware)
- Linksys E9450-SG firmware version 1.2.00.052
- Deployments exposing the device web interface to untrusted Wi-Fi or LAN segments
Discovery Timeline
- 2025-12-19 - CVE-2025-52692 published to the National Vulnerability Database
- 2026-06-17 - Entry last modified in the NVD database
Technical Details for CVE-2025-52692
Vulnerability Analysis
The Linksys E9450-SG exposes a web-based administration interface used to manage router settings, wireless configuration, and network services. CVE-2025-52692 stems from missing authentication checks on specific administrative endpoints reachable through the device HTTP interface. When the router receives a specifically crafted URL targeting these endpoints, it processes the request and executes the requested administrative action without verifying that the requester is an authenticated administrator.
The vulnerability carries a confidentiality, integrity, and availability impact because privileged router functions can modify routing, DNS, firewall, and credential settings. The EPSS probability is 5.622% (percentile 91.97), indicating elevated relative likelihood of exploit development for this class of consumer router flaw.
Root Cause
The root cause is improper enforcement of access control on administrative URLs [CWE-306]. The web server fails to validate session tokens or authentication state before dispatching certain administrative handlers. Requests reach privileged code paths through URL parameters that bypass the login gate normally enforced on the management console.
Attack Vector
The attack vector is adjacent network, meaning the attacker must be on the same logical network as the router. This includes wireless clients on the broadcast Wi-Fi network, wired LAN hosts, or guest VLANs that can route to the management interface. No user interaction and no prior credentials are required. An attacker sends a single crafted HTTP request to the router management endpoint and receives the privileged response.
Verified exploit code is not publicly available at the time of publication. Technical specifics are described in the CSA Security Alert AL-2025-118.
Detection Methods for CVE-2025-52692
Indicators of Compromise
- Unexpected HTTP requests to administrative URIs on the router from non-administrator LAN clients
- Configuration changes to DNS servers, port forwarding rules, or remote management settings without administrator action
- New or modified firewall rules and unexpected outbound connections originating from the router
- Unfamiliar wireless SSID configuration, guest network changes, or altered admin credentials
Detection Strategies
- Capture and inspect HTTP traffic to the router management IP for requests targeting administrative endpoints without prior authenticated session establishment
- Compare current router configuration against a known-good baseline to flag unauthorized changes
- Enable router syslog forwarding to a central log collector and alert on administrative actions performed outside maintenance windows
Monitoring Recommendations
- Forward router logs into a centralized logging or SIEM platform and alert on configuration-change events
- Monitor LAN segments for clients scanning the router management port (TCP/80, TCP/443)
- Track DNS resolver settings on client devices for unexpected changes that suggest router-level hijack
How to Mitigate CVE-2025-52692
Immediate Actions Required
- Restrict access to the router web management interface to a dedicated management VLAN or trusted hosts only
- Disable remote management and ensure the administration interface is not exposed to guest Wi-Fi networks
- Rotate the administrator password and review router configuration for unauthorized modifications
- Subscribe to Linksys security notifications and apply firmware updates as soon as a fixed version is released
Patch Information
At the time of publication, no vendor patch URL is listed in the NVD record for firmware version 1.2.00.052. Refer to the CSA Security Alert AL-2025-118 and the Linksys support site for updated firmware availability and installation instructions.
Workarounds
- Segment the router management interface onto an isolated VLAN reachable only from administrator workstations
- Disable guest network bridging to the LAN and block client-to-client traffic where supported
- Replace the affected device with a supported model if a patched firmware version is not made available
- Apply ACLs on upstream switches to deny HTTP and HTTPS traffic to the router management address from untrusted hosts
# Example: restrict access to the router management interface from a Linux gateway
# Allow only the administrator workstation 192.0.2.10 to reach the router at 192.0.2.1
iptables -I FORWARD -d 192.0.2.1 -p tcp -m multiport --dports 80,443 -s 192.0.2.10 -j ACCEPT
iptables -I FORWARD -d 192.0.2.1 -p tcp -m multiport --dports 80,443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
