CVE-2021-30583 in Chrome
Summary
by MITRE • 08/04/2021
Insufficient policy enforcement in image handling in iOS in Google Chrome on iOS prior to 92.0.4515.107 allowed a remote attacker to leak cross-origin data via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-30583 represents a critical security flaw in the image handling mechanisms of Google Chrome on iOS platforms. This issue stems from insufficient policy enforcement within the browser's cross-origin resource sharing implementation, specifically affecting versions prior to 92.0.4515.107. The flaw operates at the intersection of web security boundaries where legitimate image processing operations can be exploited to bypass intended security restrictions. The vulnerability is particularly concerning because it leverages the browser's rendering engine capabilities to execute unauthorized data leakage operations across different origin domains. This type of flaw directly impacts the fundamental security model of web browsers where same-origin policies are designed to prevent unauthorized access to resources from different domains. The vulnerability is classified under CWE-284 which specifically addresses insufficient access control mechanisms, demonstrating how improper enforcement of access restrictions can lead to information disclosure vulnerabilities.
The technical exploitation of this vulnerability occurs through crafted HTML pages that manipulate image loading and processing behaviors to extract cross-origin data. Attackers can construct malicious web pages that leverage the browser's image handling routines to perform unauthorized data access operations. When Chrome processes these specially crafted images, the insufficient policy enforcement allows the browser to leak information from resources that should be restricted by cross-origin policies. The attack vector exploits the gap between the intended security boundaries and the actual implementation of image processing controls within the iOS Chrome browser. This particular flaw demonstrates how image processing components can become attack surfaces when proper security checks are not implemented at the point of resource consumption. The vulnerability essentially creates a pathway for cross-origin data exfiltration through legitimate browser functionality, bypassing normal security mechanisms that should prevent such operations.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. An attacker could leverage this flaw to gather sensitive data from multiple origins, potentially including user credentials, personal information, or confidential business data. The cross-origin nature of the data leakage means that the attack could span multiple domains and applications, amplifying the potential damage. This vulnerability affects users of iOS devices who rely on Chrome for web browsing, creating a significant risk for organizations where mobile users access sensitive applications. The remote exploitation aspect means that users do not need to interact with malicious content directly, as the attack can occur through standard web browsing activities. The vulnerability's impact is particularly severe in environments where mobile security is paramount, such as financial institutions, healthcare organizations, or government agencies that handle sensitive information.
Mitigation strategies for CVE-2021-30583 require immediate updates to affected Chrome versions to ensure proper policy enforcement is implemented. Users should upgrade to Chrome version 92.0.4515.107 or later where the vulnerability has been patched. Organizations should implement network monitoring to detect potential exploitation attempts and ensure all mobile devices are kept current with security updates. Browser vendors should enhance their policy enforcement mechanisms for image handling components and conduct thorough security reviews of all resource processing functions. The fix addresses the root cause by implementing proper access control checks during image processing operations, ensuring that cross-origin restrictions are properly enforced. Security teams should also consider implementing additional network-level protections such as content filtering and web application firewalls to provide defense-in-depth against similar attacks. This vulnerability highlights the importance of comprehensive security testing across all browser components, particularly those handling user-generated content or external resources, and demonstrates how seemingly benign functionality can become attack vectors when security controls are insufficient.