Overview
A critical vulnerability, designated as CVE-2025-45842, has been discovered in the TOTOLINK NR1800X V9.1.0u.6681_B20230703. This vulnerability is due to an authenticated stack overflow that can be triggered through the ssid5g parameter in the setWiFiEasyCfg function. This vulnerability poses a considerable threat to the integrity, availability, and confidentiality of the system. Entities that utilize the TOTOLINK NR1800X in their network infrastructure should be aware of this issue and take immediate action to mitigate its potential impacts.
Vulnerability Summary
CVE ID: CVE-2025-45842
Severity: Critical (8.8)
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
TOTOLINK NR1800X | V9.1.0u.6681_B20230703
How the Exploit Works
The vulnerability is an authenticated stack overflow, exploitable via the ssid5g parameter in the setWiFiEasyCfg function. An attacker with network access and low-level privileges can send a specially crafted HTTP request to the target device. This request would contain an overly long string in the ssid5g parameter, which would cause a buffer overflow in the stack. If successful, the overflow can lead to arbitrary code execution, potentially resulting in a full system compromise or data leakage.
Conceptual Example Code
Here is a conceptual example of how a malicious HTTP request targeting this vulnerability might look. This is a simplified representation and actual exploit code may vary significantly.
POST /setWiFiEasyCfg HTTP/1.1
Host: target_device_ip
Content-Type: application/x-www-form-urlencoded
Authorization: Basic base64_credentials
ssid5g=A*10000In the above code block, `A*10000` represents a string of 10,000 ‘A’ characters, which would exceed the buffer limit and trigger the stack overflow. The `base64_credentials` would be the Base64-encoded username and password of an authenticated user account on the target device.
Recommended Mitigation
The best course of action to mitigate this vulnerability is to apply the patch provided by the vendor. If the patch is not yet available or cannot be applied immediately, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as temporary mitigation. These systems should be configured to block or alert on HTTP requests containing unusually large ssid5g parameter values.