CVE-2020-7696 in react-native-fast-image
Summary
by MITRE
This affects all versions of package react-native-fast-image. When an image with source={{uri: "...", headers: { host: "somehost.com", authorization: "..." }} is loaded, all other subsequent images will use the same headers, this can lead to signing credentials or other session tokens being leaked to other servers.
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Analysis
by VulDB Data Team • 11/04/2020
The vulnerability identified as CVE-2020-7696 represents a critical security flaw in the react-native-fast-image package that affects all versions of this popular mobile image loading library. This issue stems from improper header handling within the image loading mechanism, creating a persistent security risk that extends far beyond the initial compromised request. The vulnerability operates through a fundamental design flaw where the package fails to properly isolate HTTP headers between individual image requests, leading to cross-contamination of authentication and session data across multiple subsequent requests.
The technical implementation of this vulnerability occurs when a malicious or compromised image request is processed with specific URI and header parameters. When an image source is defined with a URI containing path traversal sequences such as "..." combined with custom headers including host and authorization fields, the library's internal state management fails to reset the header context. This results in all subsequent image loading operations inheriting the previously specified headers, effectively creating a persistent header injection vulnerability that can be exploited across the entire application session.
The operational impact of CVE-2020-7696 extends beyond simple information disclosure, as it creates a vector for credential leakage that can compromise entire user sessions and backend authentication systems. Attackers can leverage this vulnerability to extract sensitive session tokens, API keys, and other authorization credentials that are automatically included in subsequent image requests. This behavior directly aligns with CWE-200, which addresses information exposure, and represents a significant risk to applications that rely on header-based authentication mechanisms. The vulnerability essentially creates a persistent backdoor where authentication state can be leaked to unintended servers, potentially allowing unauthorized access to protected resources and services.
From an adversary perspective, this vulnerability maps directly to several ATT&CK techniques including T1566 for credential access through social engineering and T1071 for application layer protocol usage. The attack surface expands significantly as any application using react-native-fast-image becomes vulnerable to header leakage attacks, particularly those that implement token-based authentication or session management. The impact is particularly severe in mobile applications where users may be authenticated to multiple services through header-based mechanisms, creating a cascading effect of potential credential compromise.
Mitigation strategies for CVE-2020-7696 require immediate attention through package version updates and implementation of proper header isolation mechanisms. Organizations should prioritize upgrading to the latest stable version of react-native-fast-image where the header handling has been corrected to ensure proper context separation between requests. Additionally, developers should implement manual header validation and sanitization within their application code, particularly for any custom image loading implementations that may be vulnerable to similar header contamination issues. The vulnerability highlights the importance of proper state management in mobile application libraries and serves as a reminder of the critical security considerations required when handling authentication credentials in client-side applications. Security teams should also implement monitoring for unauthorized header usage patterns that could indicate exploitation attempts, while developers should adopt more rigorous input validation practices for all HTTP request parameters.