CVE-2025-29514 is a security vulnerability identified in the D-Link DSL-7740C router, specifically affecting the firmware version DSL7740C.V6.TR069.20211230. The flaw resides in the config.xgi function, which is responsible for handling configuration file requests. Due to incorrect access control mechanisms, an attacker can craft a specially designed web request that allows unauthorized downloading of the router's configuration file. This configuration file typically contains sensitive information such as network settings, administrator credentials, and possibly stored passwords or keys. The vulnerability arises because the device fails to properly authenticate or authorize the request before serving the configuration file, effectively exposing critical device data to any attacker capable of sending the crafted request. Although no known exploits are currently reported in the wild, the vulnerability's nature makes it a significant risk if weaponized. The absence of a CVSS score suggests this is a newly published vulnerability with limited public analysis, but the technical details indicate a direct confidentiality breach vector without requiring user interaction or authentication.

For European organizations, this vulnerability poses a serious threat to network security and privacy. Compromise of router configuration files can lead to exposure of administrative credentials and network topology details, enabling attackers to gain persistent access, intercept or redirect traffic, and potentially launch further attacks within the internal network. Given that D-Link DSL-7740C devices are often deployed in small to medium business environments and residential settings, exploitation could lead to widespread compromise of critical communication infrastructure. The confidentiality breach could result in data leakage, unauthorized network access, and disruption of services. Additionally, attackers could modify configurations to create backdoors or weaken security controls, impacting integrity and availability. The lack of known exploits currently provides a window for mitigation, but the ease of exploitation (no authentication required) increases the urgency for European entities to address this vulnerability proactively.

Organizations should immediately identify any deployments of the D-Link DSL-7740C router with the affected firmware version. Since no official patches or firmware updates are currently linked, mitigation should focus on network-level controls: restrict access to the router's management interface to trusted IP addresses only, preferably via VPN or internal network segments. Disable remote management features if not essential. Employ network monitoring to detect unusual HTTP requests targeting config.xgi or attempts to download configuration files. Change default administrative credentials and enforce strong password policies to reduce risk if configuration files are exposed. Consider segmenting networks to isolate vulnerable devices from critical infrastructure. Engage with D-Link support channels to obtain firmware updates or advisories. Finally, implement regular vulnerability scanning and penetration testing to detect exploitation attempts and verify mitigation effectiveness.