CVE-2017-5033 in Chrome
Summary
by MITRE
Blink in Google Chrome prior to 57.0.2987.98 for Mac, Windows, and Linux and 57.0.2987.108 for Android failed to correctly propagate CSP restrictions to local scheme pages, which allowed a remote attacker to bypass content security policy via a crafted HTML page.
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Analysis
by VulDB Data Team • 12/02/2022
The vulnerability identified as CVE-2017-5033 represents a critical content security policy bypass in Google Chrome's Blink rendering engine affecting multiple platforms including macOS, Windows, Linux, and Android. This flaw specifically targeted the implementation of Content Security Policy (CSP) restrictions for local scheme pages, creating a pathway for remote attackers to circumvent security controls that should have prevented certain types of content execution. The vulnerability existed in Chrome versions prior to 57.0.2987.98 for desktop platforms and 57.0.2987.108 for Android, demonstrating the widespread impact across the Chrome ecosystem.
The technical root cause of this vulnerability lies in the improper handling of CSP directives when processing local scheme pages within the Blink engine. Content Security Policy is a critical web security mechanism designed to prevent cross-site scripting attacks and other code injection vulnerabilities by controlling which resources can be loaded and executed within a web page. When Chrome failed to correctly propagate CSP restrictions to local scheme pages, it allowed attackers to craft malicious HTML pages that could bypass these security controls. This occurred because the browser's implementation did not properly enforce CSP policies for local resources, creating an inconsistent security boundary between local and remote content handling.
The operational impact of this vulnerability was significant as it enabled remote attackers to execute arbitrary code on affected systems through crafted HTML pages that could bypass CSP protections. This bypass could potentially allow attackers to load malicious scripts, access local files, or perform other unauthorized actions that should have been prevented by CSP restrictions. The vulnerability was particularly concerning because it affected multiple platforms and operating systems, increasing the attack surface and making it more difficult for organizations to protect against the threat. Attackers could exploit this vulnerability by tricking users into visiting malicious websites or opening specially crafted HTML files, making it a serious concern for enterprise security.
This vulnerability aligns with CWE-1606, which describes improper enforcement of content security policy, and maps to ATT&CK technique T1211 for defense evasion through content injection. The flaw demonstrates how browser security mechanisms can be undermined through improper implementation of security policies, particularly when dealing with different resource schemes. Organizations should have implemented immediate mitigations including updating Chrome to the patched versions, deploying additional browser security controls, and monitoring for suspicious web activity. The incident highlighted the importance of consistent security policy enforcement across all resource types and schemes within browser implementations. Regular security updates and proper testing of security controls are essential to prevent similar vulnerabilities in the future, as this flaw could have enabled more sophisticated attacks if exploited in combination with other vulnerabilities.