CVE-2025-29517 in DSL-7740C
Summary
by MITRE • 08/25/2025
D-Link DSL-7740C with firmware DSL7740C.V6.TR069.20211230 was discovered to contain a command injection vulnerability via the traceroute6 function.
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability identified as CVE-2025-29517 affects D-Link DSL-7740C routers running firmware version DSL7740C.V6.TR069.20211230 and represents a critical command injection flaw within the traceroute6 function. This issue resides in the network infrastructure device's web interface implementation where user-supplied input is not properly sanitized before being passed to system commands. The traceroute6 function specifically handles IPv6 traceroute operations and serves as the attack vector for this vulnerability. The flaw allows an attacker to inject malicious commands that will be executed with the privileges of the web server process, typically running with elevated permissions on the device. This represents a fundamental breakdown in input validation and command execution handling within the router's firmware. The vulnerability is particularly concerning because it affects a core networking function that should be safely accessible to legitimate users while remaining immune to malicious input manipulation.
The technical implementation of this command injection vulnerability stems from improper sanitization of user input parameters within the traceroute6 function. When a user submits a traceroute6 request through the web interface, the system accepts the destination address without adequate validation or escaping of special characters. This allows attackers to append malicious commands that get executed as part of the underlying system call. The vulnerability aligns with CWE-77 and CWE-88 categories, representing command injection through improper input handling where user-controllable data flows directly into system command execution contexts. The flaw demonstrates a classic lack of proper input filtering and command escaping mechanisms that should be implemented according to industry best practices. Attackers can exploit this by crafting specific input that includes shell metacharacters such as semicolons, ampersands, or backticks that would be interpreted by the command processor, leading to arbitrary code execution on the device.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete system compromise of the affected D-Link router. An attacker with access to the network can potentially gain root-level privileges on the device, allowing them to modify network configurations, redirect traffic, install malicious software, or use the device as a pivot point for attacking other systems within the local network. The vulnerability affects the device's core network functionality and can be exploited without requiring authentication for the web interface, making it particularly dangerous in environments where such devices are exposed to untrusted networks. Network traffic interception becomes possible, and the device could be used to conduct man-in-the-middle attacks or serve as a command and control node for broader network operations. This vulnerability undermines the fundamental security assumptions of network infrastructure devices and could enable attackers to establish persistent access points within the network topology.
Mitigation strategies for CVE-2025-29517 should prioritize immediate firmware updates from D-Link to address the command injection vulnerability in the traceroute6 function. Organizations should implement network segmentation to limit access to administrative interfaces and ensure that only authorized personnel can interact with the device configuration. Network monitoring should be enhanced to detect unusual traffic patterns that might indicate exploitation attempts, particularly around the traceroute6 functionality. Access controls should be enforced through strong authentication mechanisms and network access control lists that restrict administrative access to the device. The implementation of web application firewalls and input validation controls can provide additional layers of protection against similar injection attacks. Organizations should also consider disabling unnecessary services and functions on the device to reduce the attack surface. Security teams should monitor for any indicators of compromise and ensure that all network devices are regularly updated with the latest security patches to prevent exploitation of known vulnerabilities. This vulnerability highlights the importance of maintaining up-to-date firmware and implementing proper input validation across all network infrastructure components.