CVE-2024-7179 Overview
CVE-2024-7179 is a buffer overflow vulnerability affecting TOTOLINK A3600R routers running firmware version 4.1.2cu.5182_B20201102. The flaw resides in the setParentalRules function within /cgi-bin/cstecgi.cgi. Attackers can manipulate the startTime and endTime arguments to trigger a stack-based buffer overflow [CWE-120]. The vulnerability is exploitable remotely over the network and requires only low privileges. Public disclosure includes proof-of-concept details, increasing exploitation risk. The vendor was contacted before disclosure but did not respond, leaving affected devices without an official patch.
Critical Impact
Remote authenticated attackers can trigger a buffer overflow in the router's CGI handler, potentially leading to arbitrary code execution or device compromise.
Affected Products
- TOTOLINK A3600R router hardware
- TOTOLINK A3600R firmware version 4.1.2cu.5182_B20201102
- Deployments exposing the router web management interface
Discovery Timeline
- 2024-07-29 - CVE-2024-7179 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-7179
Vulnerability Analysis
The vulnerability is a classic buffer overflow in the TOTOLINK A3600R router firmware. The setParentalRules function handles requests submitted to the /cgi-bin/cstecgi.cgi endpoint. Two user-supplied parameters, startTime and endTime, are copied into fixed-size stack buffers without proper length validation.
When an attacker submits overly long values for these parameters, the copy operation overflows adjacent stack memory. This overwrites saved return addresses and control structures within the process. On MIPS-based embedded devices such as the A3600R, successful overflow exploitation commonly leads to arbitrary code execution.
The vulnerability is network-reachable, requiring only low privileges and no user interaction. Because TOTOLINK did not respond to disclosure, no vendor patch is available.
Root Cause
The root cause is the absence of bounds checking on the startTime and endTime parameters before they are written into stack-allocated buffers. The CGI binary cstecgi.cgi uses unsafe string handling routines that trust attacker-controlled input length. This maps to CWE-120: Buffer Copy without Checking Size of Input.
Attack Vector
An authenticated attacker on the same network as the router sends a crafted HTTP POST request to /cgi-bin/cstecgi.cgi targeting the setParentalRules action. The request body contains oversized startTime or endTime values designed to overwrite the stack. Exploitation can crash the router, cause denial of service, or execute attacker-supplied shellcode with the privileges of the CGI process.
The vulnerability mechanism and reproduction steps are documented in the GitHub IoT Vulnerability Documentation.
Detection Methods for CVE-2024-7179
Indicators of Compromise
- Unexpected reboots or crashes of the TOTOLINK A3600R router
- HTTP POST requests to /cgi-bin/cstecgi.cgi containing abnormally long startTime or endTime parameter values
- Unusual outbound connections originating from the router after receiving crafted requests
- Modified router configuration, DNS settings, or firmware integrity failures
Detection Strategies
- Inspect network traffic for HTTP requests referencing the setParentalRules action with parameter values exceeding expected time-format lengths
- Deploy intrusion detection signatures that flag oversized parameters submitted to cstecgi.cgi
- Correlate router log anomalies with authentication events to identify low-privileged accounts issuing malformed requests
Monitoring Recommendations
- Log and review all administrative access to the router web interface, including source IP and authenticated user
- Monitor for repeated malformed HTTP POST requests to CGI endpoints on internal network segments
- Track firmware integrity and configuration changes through periodic audits
How to Mitigate CVE-2024-7179
Immediate Actions Required
- Restrict access to the router's web management interface to trusted internal hosts only
- Disable remote administration on the WAN interface if enabled
- Rotate administrative credentials and enforce strong, unique passwords
- Segment the router from sensitive network zones until a fix is available
Patch Information
No vendor patch is available. The TOTOLINK vendor was contacted about this disclosure but did not respond. Affected organizations should evaluate whether the A3600R remains suitable for their environment given the lack of vendor security response. Consider replacing the device with a supported router platform.
Workarounds
- Block external access to /cgi-bin/cstecgi.cgi at an upstream firewall or gateway
- Place the router behind a network access control layer that limits which clients can reach the management interface
- Disable the parental controls feature if the underlying code path can be avoided through configuration
- Replace the affected device with a currently supported router where feasible
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
