CVE-2017-0929 in DotNetNuke
Summary
by MITRE
DNN (aka DotNetNuke) before 9.2.0 suffers from a Server-Side Request Forgery (SSRF) vulnerability in the DnnImageHandler class. Attackers may be able to access information about internal network resources.
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Analysis
by VulDB Data Team • 04/16/2025
The vulnerability identified as CVE-2017-0929 represents a critical Server-Side Request Forgery issue within DNN (DotNetNuke) platforms prior to version 9.2.0. This flaw exists within the DnnImageHandler class, which processes image requests and handles various URL parameters that determine the source and destination of image resources. The vulnerability stems from insufficient validation of user-supplied input parameters that are used to construct HTTP requests to external or internal resources. Attackers can exploit this weakness by manipulating the input parameters to redirect the application's image handling functionality to internal network addresses or services that should remain inaccessible to external users.
The technical implementation of this SSRF vulnerability allows malicious actors to leverage the DNN application's legitimate image processing capabilities to make HTTP requests to arbitrary URLs. When the DnnImageHandler processes an image request, it accepts parameters that specify the source of the image, which can include URLs pointing to internal resources such as databases, internal APIs, or other network services. The lack of proper input sanitization and validation means that an attacker can inject specially crafted URLs that bypass normal network access controls and gain visibility into internal systems. This occurs because the application treats the user-provided URLs as legitimate requests without sufficient verification of their destination or security implications.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to map internal network topologies, identify running services, and potentially access sensitive internal resources that should be protected by firewalls and network segmentation. An attacker could use this vulnerability to probe internal systems for open ports, discover internal web applications, or even attempt to access internal databases or administrative interfaces. The vulnerability is particularly dangerous because it leverages the application's legitimate functionality to perform unauthorized network operations, making detection more difficult and potentially allowing attackers to maintain persistent access to internal resources. This type of vulnerability aligns with CWE-918, which specifically addresses Server-Side Request Forgery vulnerabilities where applications fail to properly validate or sanitize user input used in making HTTP requests.
Organizations utilizing DNN platforms before version 9.2.0 face significant risk exposure from this vulnerability, as it can be exploited without requiring authentication or special privileges within the application itself. The exploitation typically requires only the ability to submit requests to the image handler endpoint, which is often publicly accessible. Mitigation strategies include upgrading to DNN version 9.2.0 or later, which includes proper input validation and URL sanitization mechanisms. Additionally, implementing network-level restrictions to prevent outbound requests from the application server to internal resources, configuring proper firewall rules, and monitoring for unusual outbound network activity can help reduce the risk. Security teams should also consider implementing web application firewalls and input validation controls that specifically target SSRF attack patterns, aligning with ATT&CK technique T1071.004 for Application Layer Protocol: DNS to restrict malicious DNS queries that may be part of broader exploitation attempts. The vulnerability demonstrates the importance of validating all user inputs and implementing proper access controls even within trusted application components.