CVE-2015-1211 in Chrome
Summary
by MITRE
The OriginCanAccessServiceWorkers function in content/browser/service_worker/service_worker_dispatcher_host.cc in Google Chrome before 40.0.2214.111 on Windows, OS X, and Linux and before 40.0.2214.109 on Android does not properly restrict the URI scheme during a ServiceWorker registration, which allows remote attackers to gain privileges via a filesystem: URI.
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Analysis
by VulDB Data Team • 03/08/2022
The vulnerability identified as CVE-2015-1211 represents a critical privilege escalation flaw in Google Chrome's service worker implementation that existed across multiple operating systems and platforms. This issue specifically affects the OriginCanAccessServiceWorkers function within the service_worker_dispatcher_host.cc file, which governs how service workers handle cross-origin access controls. The flaw manifests when Chrome fails to properly validate URI schemes during service worker registration processes, creating a pathway for malicious actors to exploit the browser's security model.
The technical implementation of this vulnerability stems from insufficient input validation within Chrome's service worker architecture. When service workers attempt to register with specific origins, the system should enforce strict URI scheme restrictions to prevent unauthorized access to local file systems. However, the vulnerable code path allows filesystem: URIs to bypass these security checks, effectively granting remote attackers the ability to execute code with elevated privileges. This occurs because the OriginCanAccessServiceWorkers function does not adequately validate that the URI scheme adheres to the expected security boundaries, particularly when dealing with filesystem protocols.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to gain access to sensitive system resources that should remain isolated from web content. Attackers can leverage this flaw to register service workers with filesystem: URIs, potentially allowing them to read, modify, or execute arbitrary files on the victim's system. This capability directly violates Chrome's security model of isolating web content from local file systems, creating a significant attack surface that could be exploited for data exfiltration, system compromise, or further lateral movement within a compromised environment. The vulnerability affects all supported platforms including Windows, macOS, Linux, and Android, making it particularly dangerous due to its widespread applicability.
This vulnerability aligns with CWE-20, which describes improper input validation, and represents a specific instance of privilege escalation through inadequate access control mechanisms. The attack vector follows patterns consistent with the ATT&CK framework's privilege escalation techniques, particularly those involving exploitation of browser vulnerabilities to gain elevated system access. Organizations should consider this vulnerability as part of a broader attack chain that could lead to full system compromise, especially when combined with other browser-based exploits. The remediation process requires updating to Chrome versions 40.0.2214.111 for desktop platforms and 40.0.2214.109 for Android, which implement proper URI scheme validation and strengthen the service worker registration process. Security teams should prioritize patching this vulnerability given its potential for remote code execution and the fact that it affects multiple operating systems and device types.