Fastly StoreMapper Content-Security-Policy Bypass Scanner

Fastly StoreMapper is used by businesses to integrate location-based services into web applications. This product is commonly utilized by companies with multiple physical locations to provide store locator features on their websites. Organizations leverage Fastly StoreMapper for its performance and scalability to ensure a seamless user experience. The software also aids in enhancing customer engagement by providing real-time data for nearest location services. Retail chains, franchises, and service providers frequently incorporate this tool to improve their geographical accessibility to customers. With its robust API, Fastly StoreMapper integrates easily into existing web platforms.

Cross-Site Scripting (XSS) refers to a security vulnerability that allows attackers to inject malicious scripts into webpages viewed by other users. In the context of Fastly StoreMapper, an XSS vulnerability could be exploited to execute scripts in users' browsers without their knowledge. This type of vulnerability can lead to user data theft, session hijacking, and unauthorized actions performed on behalf of the users. XSS vulnerabilities are significant as they compromise the trust between users and web applications. Protecting against such vulnerabilities is crucial in maintaining the integrity and security of web services. Regular security testing and prompt patching are essential to mitigate the risks associated with XSS.

The Fastly StoreMapper vulnerability involves inadequate Content-Security-Policy (CSP) configurations, permitting XSS attacks through script injections. This vulnerability is typically exploited by injecting malicious JavaScript code via URL parameters. The endpoint {{BaseURL}} is particularly susceptible to such injections. Attackers utilize crafted payloads, like the one mentioned in the template, to bypass CSP headers and execute scripts. Key identifiers include the presence of specific patterns in headers, such as "Content-Security-Policy" combined with "fastly.net". The use of fuzzing techniques and observing script execution signals, like the variable fastly_storemapper_csp_xss, confirms the presence of this vulnerability.

The exploitation of this vulnerability could lead to various security incidents. Attackers might execute arbitrary scripts that redirect users to malicious sites or steal sensitive information, such as authentication tokens. Furthermore, compromised user accounts could be used for fraudulent transactions or unauthorized access to private data. If left unaddressed, this vulnerability could damage the affected organization's reputation, resulting in loss of customer trust and legal consequences. Businesses might also face financial losses due to potential data breaches and the need to implement extensive remediation measures post-exploitation.

REFERENCES

• https://github.com/renniepak/CSPBypass/blob/main/data.tsv