CVE-2019-5783 in Chrome
Summary
by MITRE
Missing URI encoding of untrusted input in DevTools in Google Chrome prior to 72.0.3626.81 allowed a remote attacker to perform a Dangling Markup Injection attack via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/01/2024
The vulnerability identified as CVE-2019-5783 represents a critical security flaw in Google Chrome's DevTools functionality that existed prior to version 72.0.3626.81. This issue stems from insufficient input validation and sanitization within the debugging interface, creating a pathway for malicious actors to exploit the browser's development tools. The vulnerability specifically targets the handling of untrusted input within DevTools, where proper URI encoding mechanisms were absent or inadequate. This weakness allows attackers to manipulate the browser's debugging environment through crafted HTML content, potentially compromising the integrity of the browser's rendering process. The flaw manifests when the DevTools component processes user-supplied data without adequate sanitization, enabling attackers to inject malformed markup that can persist and execute within the browser context.
The technical exploitation of this vulnerability follows a Dangling Markup Injection attack pattern that leverages the DevTools' permissive handling of untrusted data. When Chrome processes HTML content containing malicious markup within its debugging interface, the missing URI encoding prevents proper sanitization of potentially harmful input sequences. This creates a scenario where attacker-controlled data can be interpreted as executable code within the browser's rendering pipeline. The attack vector typically involves constructing a malicious HTML page that, when loaded in a context where DevTools is active, triggers the injection mechanism. The vulnerability's classification aligns with CWE-116, which addresses improper encoding of dangerous characters, and CWE-79, covering cross-site scripting flaws. The attack methodology follows patterns consistent with ATT&CK technique T1059.001, which involves command and scripting interpreter usage, particularly when the injected markup can manipulate the browser's execution environment through JavaScript injection.
The operational impact of CVE-2019-5783 extends beyond simple cross-site scripting, as it can enable more sophisticated attacks through the DevTools interface. Attackers can leverage this vulnerability to execute arbitrary code within the browser context, potentially accessing sensitive user data, performing unauthorized actions, or establishing persistent access to user sessions. The vulnerability's remote exploitation capability means that users do not need to interact with malicious content directly, as the attack can be triggered through standard web browsing activities. This makes the vulnerability particularly dangerous in environments where users may encounter malicious content through social engineering or compromised websites. The attack can be amplified through various delivery mechanisms including phishing campaigns, compromised advertising networks, or malicious web applications that utilize DevTools functionality. The vulnerability's presence in the DevTools component also means that even legitimate developers who use these debugging tools could inadvertently expose themselves to attacks when processing untrusted content.
Mitigation strategies for CVE-2019-5783 focus on both immediate remediation and long-term security hardening. The primary solution involves updating to Chrome version 72.0.3626.81 or later, which implements proper URI encoding for untrusted input within DevTools. Organizations should also implement network-level protections such as content filtering and web application firewalls to detect and block malicious content before it reaches user browsers. Browser security configurations should include disabling DevTools in production environments where possible, though this may impact legitimate debugging activities. Additional defensive measures include implementing strict content security policies that limit script execution and data injection points within web applications. Security teams should monitor for indicators of compromise related to this vulnerability, particularly unusual DevTools activity or unexpected JavaScript execution patterns. The vulnerability's resolution demonstrates the importance of proper input validation and encoding practices in browser security, aligning with industry standards that emphasize the need for robust sanitization of all user-supplied data. Organizations should also consider implementing automated security testing that includes DevTools functionality validation to prevent similar vulnerabilities from emerging in future browser versions or web applications.