CVE-2017-7852 in DCS Cameras
Summary
by MITRE
D-Link DCS cameras have a weak/insecure CrossDomain.XML file that allows sites hosting malicious Flash objects to access and/or change the device's settings via a CSRF attack. This is because of the 'allow-access-from domain' child element set to *, thus accepting requests from any domain. If a victim logged into the camera's web console visits a malicious site hosting a malicious Flash file from another Browser tab, the malicious Flash file then can send requests to the victim's DCS series Camera without knowing the credentials. An attacker can host a malicious Flash file that can retrieve Live Feeds or information from the victim's DCS series Camera, add new admin users, or make other changes to the device. Known affected devices are DCS-933L with firmware before 1.13.05, DCS-5030L, DCS-5020L, DCS-2530L, DCS-2630L, DCS-930L, DCS-932L, and DCS-932LB1.
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Analysis
by VulDB Data Team • 08/23/2024
The vulnerability identified as CVE-2017-7852 represents a critical security flaw in D-Link DCS series network cameras that stems from improper implementation of cross-domain policy mechanisms. This weakness manifests through an insecure crossdomain.xml configuration file that grants unrestricted access to camera resources, creating a significant attack surface for malicious actors. The vulnerability specifically affects multiple models within the DCS series including DCS-933L, DCS-5030L, DCS-5020L, DCS-2530L, DCS-2630L, DCS-930L, DCS-932L, and DCS-932LB1 devices. The root cause lies in the crossdomain.xml file containing an 'allow-access-from domain' element configured with a wildcard asterisk (*) value, which permits any domain to access the camera's resources without proper authentication or authorization checks.
This security flaw enables a sophisticated cross-site request forgery (CSRF) attack vector that operates through malicious Flash content hosted on compromised websites. The attack mechanism exploits the trust relationship between the victim's browser and the camera's web interface, allowing malicious actors to execute unauthorized commands without possessing valid credentials. When a victim accesses the camera's web console and subsequently visits a malicious website hosting Flash content in another browser tab, the Flash file can silently transmit requests to the victim's camera. This technique leverages the browser's automatic credential handling for same-domain requests, bypassing the need for authentication tokens or user credentials. The vulnerability effectively transforms any logged-in user session into a potential attack vector that can be exploited by remote adversaries.
The operational impact of this vulnerability extends far beyond simple information disclosure, encompassing complete unauthorized control of affected camera systems. Attackers can exploit this weakness to access live video feeds, extract sensitive operational data, modify camera configuration settings, and establish persistent access through administrative user creation. The ability to add new administrator accounts provides attackers with long-term access to the camera infrastructure, while the capacity to retrieve live feeds compromises the privacy and security of monitored environments. This vulnerability directly violates fundamental security principles of authentication and authorization, as it allows unauthenticated remote code execution against networked security devices. The attack can be executed entirely through web-based vectors without requiring physical access or specialized equipment, making it particularly dangerous for enterprise and residential security deployments.
The technical implementation of this vulnerability aligns with CWE-346, which addresses "Improper Verification of Source of a Communication Channel," and represents a classic case of insecure cross-domain policy configuration. This weakness creates an attack surface that maps directly to multiple ATT&CK techniques including T1071.004 for Application Layer Protocol: DNS and T1566 for Phishing, as attackers can craft malicious websites to deliver exploitable Flash content. Organizations should implement immediate mitigations including firmware updates to versions containing patched crossdomain.xml configurations, network segmentation to isolate affected devices, and implementation of web application firewalls to detect and block malicious cross-domain requests. Additionally, disabling Flash support in browser environments and implementing proper access controls through network-level restrictions can significantly reduce the risk exposure. The vulnerability underscores the critical importance of secure configuration management in IoT devices and highlights the need for comprehensive security testing of networked camera systems to prevent similar weaknesses in future deployments.