CVE-2024-7465: Totolink CP450 Buffer Overflow Vulnerability

CVE-2024-7465 Overview

CVE-2024-7465 is a buffer overflow vulnerability in the TOTOLINK CP450 wireless router running firmware version 4.1.0cu.747_B20191224. The flaw resides in the loginauth function within /cgi-bin/cstecgi.cgi, where the http_host argument is processed without sufficient bounds checking [CWE-120]. Attackers can exploit the issue remotely over the network to corrupt memory and potentially execute arbitrary code on the device. The vulnerability has been publicly disclosed under VulDB identifier VDB-273558, and proof-of-concept material is available. According to the advisory, the vendor was contacted prior to disclosure but did not respond.

Critical Impact

Remote attackers can trigger a buffer overflow through the http_host parameter, leading to denial of service or arbitrary code execution on affected TOTOLINK CP450 routers.

Affected Products

• TOTOLINK CP450 router (hardware)
• TOTOLINK CP450 firmware version 4.1.0cu.747_B20191224
• Deployments exposing the /cgi-bin/cstecgi.cgi web management interface

Discovery Timeline

• 2024-08-05 - CVE-2024-7465 published to NVD
• 2024-08-15 - Last updated in NVD database

Technical Details for CVE-2024-7465

Vulnerability Analysis

The vulnerability resides in the loginauth handler of cstecgi.cgi, the CGI binary that services authentication and management requests on the TOTOLINK CP450. When the binary parses incoming HTTP requests, it reads the http_host argument from the request and copies it into a fixed-size stack buffer without validating the input length. Supplying an oversized value overruns the buffer and corrupts adjacent stack memory, including saved return addresses on the MIPS-based device. Successful exploitation can crash the web service or, with a tailored payload, redirect execution flow. The attack requires network reachability to the router's management interface and works with low-privileged credentials per the CVSS vector.

Root Cause

The root cause is improper restriction of operations within the bounds of a memory buffer [CWE-120]. The loginauth function trusts the length of the http_host parameter supplied by the client and uses an unsafe string-copy routine to move the data into a stack-allocated buffer. No length check, truncation, or safer alternative such as strncpy with a verified bound is applied before the copy.

Attack Vector

Exploitation is performed over the network by sending a crafted HTTP request to /cgi-bin/cstecgi.cgi targeting the loginauth action. The attacker places an overlong string in the http_host argument or header. When the CGI binary processes the request, the overflow corrupts the stack and causes the device to crash or execute attacker-controlled data. Public proof-of-concept details are hosted in the GitHub PoC Repository and indexed in VulDB #273558.

No verified exploit code is reproduced here. Refer to the referenced research for technical details on payload construction and offsets.

Detection Methods for CVE-2024-7465

Indicators of Compromise

• HTTP POST or GET requests to /cgi-bin/cstecgi.cgi containing the loginauth action with abnormally long http_host values.
• Unexpected reboots, web interface crashes, or httpd process restarts on TOTOLINK CP450 devices.
• Outbound connections from the router to unfamiliar hosts following inbound requests to the management interface.

Detection Strategies

• Inspect web traffic to router management interfaces and flag requests where the http_host parameter exceeds expected length thresholds.
• Correlate device crash events or syslog messages from CP450 routers with preceding HTTP requests to cstecgi.cgi.
• Search archived network telemetry for the exact endpoint /cgi-bin/cstecgi.cgi paired with the loginauth keyword from untrusted source IPs.

Monitoring Recommendations

• Forward router syslog and authentication logs to a central data lake for retention and querying.
• Alert on repeated failed loginauth attempts or malformed requests targeting the CGI interface.
• Monitor the management VLAN for any access originating outside the administrative network.

How to Mitigate CVE-2024-7465

Immediate Actions Required

• Remove the CP450 management interface from any WAN-facing or untrusted network segment.
• Restrict access to /cgi-bin/cstecgi.cgi through firewall rules limiting source addresses to administrative hosts.
• Rotate administrative credentials and audit existing accounts on the device.
• Treat the device as compromised if crash artifacts or unexpected configuration changes are observed.

Patch Information

No vendor patch has been published. The disclosure advisory notes that the vendor was contacted but did not respond. Affected operators should monitor the TOTOLINK support channels for future firmware updates and consult VulDB #273558 for advisory revisions.

Workarounds

• Disable remote management on the WAN interface so the CGI endpoint is unreachable from the internet.
• Place the router behind a network firewall and permit management traffic only from a trusted jump host or VPN.
• Plan replacement of the CP450 with a supported model that receives security maintenance from the vendor.

# Example firewall rule restricting access to the router management interface
# Replace 192.0.2.10 with your administrative workstation and 10.0.0.1 with the router IP
iptables -A FORWARD -p tcp -s 192.0.2.10 -d 10.0.0.1 --dport 80 -j ACCEPT
iptables -A FORWARD -p tcp -d 10.0.0.1 --dport 80 -j DROP