OpenExchangeRates Content-Security-Policy Bypass Scanner

OpenExchangeRates is a popular service used by developers to access real-time and historical foreign exchange rates. It is widely used in financial applications and currency converters to provide users with up-to-date currency information. The service is typically integrated through its API, and developers can use it to incorporate exchange rate functionality into their applications. It is used by businesses worldwide for accurate currency transaction calculations and analytics. The flexibility of format options supported by OpenExchangeRates makes it a preferred choice for developers. The service also offers premium features and data provided through different subscription plans.

The vulnerability detected relates to a potential bypass of the Content-Security-Policy (CSP). CSP is a security feature that helps prevent cross-site scripting (XSS) attacks by specifying which content sources are valid. A CSP bypass vulnerability allows malicious code to execute scripts that are otherwise restricted by the CSP. This vulnerability poses a significant security risk as XSS exploits can be used to steal sensitive data, such as user credentials or manipulate the content displayed on a website. CSP bypass vulnerabilities are a result of either misconfigurations or unexpected script execution permissions. Identifying such vulnerabilities is crucial for maintaining web application security integrity.

The vulnerability arises from an improper configuration allowing script injection into the web application's context. The payload makes a request using the OpenExchangeRates API with a crafted script designed to circumvent the CSP settings. The vulnerable parameter is typically found in requests targeting endpoints that implement openexchangerates.org. The test uses a specially encoded script to test whether the injected script executes, bypassing CSP restrictions. Detection involves analyzing if the injected script successfully runs, indicating a bypass. The technical aspect revolves around exploiting open and improperly validated URLs that allow foreign scripts.

An exploited CSP bypass may lead to unauthorized script execution, potentially allowing attackers to impersonate users, steal session cookies, and manipulate displayed content. Malicious actors can use this as an entry point for further intrusions, facilitating more severe attacks on the system infrastructure. By exploiting this vulnerability, an attacker can perform actions like phishing through legitimate pages and escalate privileged actions on behalf of users. Malicious scripts can be used to log keystrokes, leading to the theft of sensitive information. Other consequences include defacement, malicious redirection, and data exfiltration.

REFERENCES

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