BrightSign Digital Signage SSRF Scanner

BrightSign Digital Signage Diagnostic Web Server is a crucial component used in the BrightSign digital signage media player, often employed by businesses and organizations to manage and troubleshoot digital signage systems. Its primary users include IT professionals, digital signage integrators, and technical support teams who rely on its diagnostic capabilities for efficient operations. This server enables quick identification and resolution of issues related to signage performance, ensuring continuous and effective displays. Primarily, it helps in monitoring network status, download speeds, and system health of digital signage setups. The web server is vital in environments where real-time information display and accuracy is crucial. Designed to work seamlessly with the BrightSign ecosystem, it supports a robust digital signage setup.

The Server-Side-Request-Forgery (SSRF) vulnerability found in the BrightSign Digital Signage Diagnostic Web Server allows attackers to manipulate server requests. This vulnerability occurs when external user data is improperly processed to create server-side requests, exposing the system to threats. It specifically affects the 'url' GET parameter, through which unauthorized users can influence server requests. SSRF can lead to unauthorized access of internal resources, potentially exposing sensitive data. This vulnerability highlights the risk of injection attacks where external inputs are inadequately validated. Ensuring strict input validation and server response controls is essential to mitigating SSRF risk.

Technical details of this SSRF vulnerability involve the use of the 'url' parameter in the diagnostics request setup. Affected versions parse user-supplied data without sufficient checks, forming requests intended to interact with the Download Speed Test service. Consequently, attackers can manipulate these requests to probe and exploit internal network services, posing significant security risks. Successful exploitation can allow attackers to bypass restrictions and access non-public server locations. This issue arises due to the lack of stringent validation controls on server-side parameters. Developing precise filtering mechanisms for inputs can prevent such vulnerabilities.

Exploitation of the SSRF vulnerability could have severe consequences for businesses relying on BrightSign's digital products. Attackers could manipulate internal server requests to gain unauthorized insights into sensitive internal network configurations. This can lead to potential breaches where confidential data is exposed or misused. Furthermore, intrusions may allow attackers to launch further attacks within the network, compromising additional systems. Protecting against SSRF involves implementing robust validations and restrictions for external requests. Regular security audits and updates are paramount to safeguarding against such vulnerabilities.

REFERENCES

• https://brightsign.zendesk.com/hc/en-us/articles/360056180694-Regarding-Advisory-ID-ZSL-2020-5595
• https://www.zeroscience.mk/codes/brightsign_ssrf.txt