CVE-2025-29514 in DSL-7740C
Summary
by MITRE • 08/25/2025
Incorrect access control in the config.xgi function of D-Link DSL-7740C with firmware DSL7740C.V6.TR069.20211230 allows attackers to download the configuration file via providing a crafted web request.
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability identified as CVE-2025-29514 represents a critical access control flaw within the web interface of D-Link DSL-7740C broadband routers running firmware version DSL7740C.V6.TR069.20211230. This issue resides in the config.xgi function which handles configuration file operations, creating an unauthorized access vector that could allow remote attackers to extract sensitive system configuration data. The flaw specifically affects the authentication and authorization mechanisms that should normally prevent arbitrary users from accessing administrative functions through the web management interface.
The technical implementation of this vulnerability stems from insufficient input validation and access control checks within the config.xgi endpoint. When processing web requests, the function fails to properly verify user credentials or session tokens before permitting configuration file downloads. This allows attackers to craft malicious HTTP requests that bypass normal authentication procedures and directly access the router's configuration file through a predictable URI path. The vulnerability essentially creates a backdoor pathway through the router's web interface that operates without proper authorization verification, making it particularly dangerous for network administrators who rely on these devices for network security.
The operational impact of this vulnerability extends beyond simple information disclosure, as the downloaded configuration files typically contain sensitive network parameters including administrative credentials, network settings, wireless passwords, and other critical system information. Attackers could leverage this access to gain comprehensive knowledge of the target network infrastructure, potentially enabling further attacks such as credential reuse, network reconnaissance, or lateral movement within the compromised network. The exposure of administrative credentials in particular poses a significant risk as these could be used to gain full administrative control over the device and potentially the entire network segment it serves.
This vulnerability aligns with CWE-284, which describes improper access control in software applications, and represents a classic example of insufficient authorization checks in web applications. From an adversarial perspective, this flaw maps directly to techniques described in the MITRE ATT&CK framework under the T1212 technique for exploitation of remote services, and could be categorized under T1566 for initial access through web applications. Network security professionals should recognize this as a critical vulnerability that requires immediate attention due to its remote exploitability and the sensitive data it exposes.
Mitigation strategies for this vulnerability should include immediate firmware updates from D-Link to address the access control flaw, implementation of network segmentation to limit access to administrative interfaces, and deployment of web application firewalls to monitor and filter malicious requests targeting the config.xgi endpoint. Administrators should also enforce strong authentication practices including multi-factor authentication for router management interfaces, disable unnecessary remote management features, and implement network access controls to restrict which systems can communicate with the router's web management interface. Regular security audits and network monitoring should be conducted to detect any unauthorized access attempts or anomalous traffic patterns that might indicate exploitation of this vulnerability.