CVE-2014-7948 in Chrome
Summary
by MITRE
The AppCacheUpdateJob::URLFetcher::OnResponseStarted function in content/browser/appcache/appcache_update_job.cc in Google Chrome before 40.0.2214.91 proceeds with AppCache caching for SSL sessions even if there is an X.509 certificate error, which allows man-in-the-middle attackers to spoof HTML5 application content via a crafted certificate.
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Analysis
by VulDB Data Team • 12/11/2024
The vulnerability described in CVE-2014-7948 represents a critical security flaw in Google Chrome's handling of HTML5 application cache updates within SSL sessions. This issue affects Chrome versions prior to 40.0.2214.91 and stems from a specific function within the application cache update mechanism that fails to properly validate SSL certificate integrity during the caching process. The flaw allows malicious actors to exploit a man-in-the-middle attack vector by presenting a crafted certificate that would normally trigger an SSL certificate error, yet the browser continues to cache the application content despite the certificate validation failure.
The technical implementation of this vulnerability resides in the AppCacheUpdateJob::URLFetcher::OnResponseStarted function located in content/browser/appcache/appcache_update_job.cc. This function is responsible for managing the retrieval and caching of application cache resources during SSL sessions. The flaw occurs because the function does not adequately check for X.509 certificate errors before proceeding with the caching operation, creating a scenario where the browser accepts potentially compromised certificates and continues to process the application cache data. This represents a fundamental breakdown in the certificate validation chain that should normally prevent caching operations when SSL/TLS certificate validation fails.
The operational impact of this vulnerability is severe as it enables attackers to perform sophisticated man-in-the-middle attacks against users of affected Chrome versions. By presenting a forged SSL certificate that appears legitimate to the victim's browser, attackers can intercept and modify HTML5 application content without detection. This compromise allows for the injection of malicious code, manipulation of web applications, and potential data exfiltration from applications that rely on HTML5 application cache for offline functionality. The vulnerability particularly affects web applications that depend on application cache for storing critical resources, making it a significant threat to web application integrity and user security.
This vulnerability maps directly to CWE-295, which covers "Improper Certificate Validation," and aligns with ATT&CK technique T1041, "Exfiltration Over C2 Channel," as it enables attackers to manipulate cached content and potentially exfiltrate data through compromised application cache. The flaw also relates to ATT&CK technique T1557, "Adversary-in-the-Middle," as it specifically enables man-in-the-middle attacks against SSL sessions. Organizations and users should immediately update to Chrome version 40.0.2214.91 or later to remediate this vulnerability, as the patch addresses the certificate validation logic to ensure that SSL certificate errors properly abort the application cache update process. Additionally, system administrators should monitor for potential exploitation attempts and consider implementing additional network monitoring to detect anomalous application cache behavior that might indicate successful exploitation of this vulnerability.