CVE-2024-8577 Overview
CVE-2024-8577 is a buffer overflow vulnerability affecting TOTOLINK AC1200 T8 and AC1200 T10 wireless routers. The flaw resides in the setStaticDhcpRules function within /cgi-bin/cstecgi.cgi. Manipulation of the desc argument leads to a buffer overflow that attackers can trigger remotely. The vulnerability is classified under CWE-120 (Buffer Copy without Checking Size of Input). The vendor was contacted about this disclosure but did not respond, and the exploit has been publicly disclosed.
Critical Impact
Remote attackers with low privileges can trigger memory corruption in the router's web management interface, potentially leading to arbitrary code execution or device compromise.
Affected Products
- TOTOLINK AC1200 T8 firmware version 4.1.5cu.861_B20230220
- TOTOLINK AC1200 T10 firmware version 4.1.8cu.5207
- TOTOLINK AC1200 T8 and T10 hardware devices
Discovery Timeline
- 2024-09-08 - CVE-2024-8577 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-8577
Vulnerability Analysis
The vulnerability exists in the setStaticDhcpRules handler exposed through the Common Gateway Interface (CGI) binary at /cgi-bin/cstecgi.cgi. This endpoint processes static DHCP rule configuration requests submitted through the router's web management interface. The desc parameter, which stores a user-supplied description for a static DHCP entry, is copied into a fixed-size stack or heap buffer without proper bounds checking.
An authenticated attacker sending an overly long desc value overflows the destination buffer. This corrupts adjacent memory regions and can overwrite control-flow data such as return addresses or function pointers on affected TOTOLINK firmware. Successful exploitation may result in denial of service or arbitrary code execution in the context of the CGI process, which typically runs with elevated privileges on embedded devices.
Root Cause
The root cause is missing input length validation in the setStaticDhcpRules function. The firmware uses unsafe string handling routines to copy the desc argument into a fixed-length buffer. TOTOLINK's cstecgi.cgi binary does not enforce a maximum length on this parameter before performing the copy operation, matching the pattern documented under CWE-120.
Attack Vector
Exploitation requires network access to the router's web management interface and low-level authenticated privileges. An attacker submits a crafted HTTP POST request to /cgi-bin/cstecgi.cgi invoking the setStaticDhcpRules action with an oversized desc field. Because the management interface is typically accessible on the LAN, an attacker on the same network segment, or one who reaches the WAN-side interface if remote management is enabled, can trigger the flaw. Technical exploitation notes are documented in the GitHub IoT Vulnerability Notes.
No verified proof-of-concept code is included here. See the linked advisory for exploitation details.
Detection Methods for CVE-2024-8577
Indicators of Compromise
- HTTP POST requests to /cgi-bin/cstecgi.cgi containing the setStaticDhcpRules action with unusually long desc parameter values.
- Unexpected crashes, restarts, or watchdog reboots of the router's HTTP daemon or CGI process.
- Unauthorized modifications to the static DHCP reservation table on affected devices.
Detection Strategies
- Inspect web management interface logs for requests to cstecgi.cgi containing parameter values that exceed reasonable length thresholds for description fields.
- Deploy network intrusion detection signatures that alert on POST bodies to the CGI endpoint containing topicurl=setStaticDhcpRules with desc values over a few hundred bytes.
- Monitor router syslog or remote logging streams for repeated CGI process crashes indicative of exploitation attempts.
Monitoring Recommendations
- Restrict administrative interface exposure and log every authenticated session that modifies DHCP configuration.
- Baseline normal HTTP request sizes to the router management interface and alert on statistical outliers.
- Track outbound connections from the router itself, which may indicate post-exploitation command-and-control activity.
How to Mitigate CVE-2024-8577
Immediate Actions Required
- Disable remote (WAN-side) access to the router's web management interface to reduce the attack surface.
- Enforce strong administrator credentials and rotate any default passwords still in use on AC1200 T8 and T10 devices.
- Segment the router management network so that only trusted administrative hosts can reach /cgi-bin/cstecgi.cgi.
- Audit the static DHCP reservation table for unauthorized entries that may indicate prior exploitation attempts.
Patch Information
At the time of publication, no vendor-supplied patch is available. According to the disclosure metadata, TOTOLINK was contacted early about this issue but did not respond. Monitor the TOTOLINK Official Website for firmware updates addressing the AC1200 T8 (4.1.5cu.861_B20230220) and T10 (4.1.8cu.5207) versions. Additional tracking references are available in the VulDB Entry #276811.
Workarounds
- Place affected TOTOLINK routers behind a firewall that filters unauthorized access to TCP ports serving the web management interface.
- Consider replacing end-of-support consumer routers with actively maintained hardware if no vendor patch is released.
- Use a VPN or jump host for legitimate remote administration instead of exposing the CGI endpoint to untrusted networks.
# Example iptables rule restricting router management access to a trusted admin subnet
iptables -A INPUT -p tcp --dport 80 -s 192.0.2.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.0.2.0/24 -j ACCEPT
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.
