Overview
A significant vulnerability has been identified in the Tenda AC23 router, specifically affecting versions up to 16.03.07.52. The vulnerability, cataloged as CVE-2025-10803, resides in the sscanf function of the “/goform/SetPptpServerCfg” file, within the HTTP POST Request Handler component. This vulnerability poses a serious threat to users of the router, as it allows potential remote system compromise or data leakage. Given the prevalence of Tenda AC23 routers in both home and corporate environments, the potential for harm is considerable.
Vulnerability Summary
CVE ID: CVE-2025-10803
Severity: High, CVSS Score 8.8
Attack Vector: Network (Remote)
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
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Product | Affected Versions
Tenda AC23 | Up to 16.03.07.52
How the Exploit Works
The vulnerability allows an attacker to overflow the buffer by manipulating the ‘startIp’ argument in the HTTP POST Request. This manipulation can lead to unexpected behavior, including the execution of arbitrary code. The exploit can be launched remotely, without the need for user interaction or privileged access.
Conceptual Example Code
Here is a conceptual example of how an HTTP request exploiting this vulnerability might look:
POST /goform/SetPptpServerCfg HTTP/1.1
Host: target.router.ip
Content-Type: application/x-www-form-urlencoded
startIp=255.255.255.255%00[insert malicious code here]In this example, an attacker would replace [insert malicious code here] with their desired payload, typically designed to either compromise the system or exfiltrate data.
Mitigation
Until Tenda offers a definitive patch, it is recommended to use a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) as a temporary mitigation against this vulnerability. These systems can help by monitoring and blocking suspicious activities, thus reducing the risk of exploitation. Regularly updating all software and firmware, including routers, is an essential practice in maintaining a secure environment.
