Chrome Extensions Incorrect Authorization Privilege Escalation

Technical Analysis

The flaw resides in Chrome's Extensions subsystem where insufficient authorization checks allow a malicious or crafted HTML page to escape normal access restrictions and reach privileged internal pages (e.g., chrome:// or extension-privileged contexts), potentially enabling further exploitation such as extension manipulation or sandbox escape chaining. Exploitation requires the victim to load attacker-controlled HTML, likely via a malicious website or compromised ad content, making it a client-side, remote attack vector with no authentication required. The discrepancy between the reported CVSS 9.8 and Chromium's own 'Low' severity rating suggests the NVD score may be auto-generated or overly conservative pending full vendor triage; analysts should weight the Chromium severity more heavily until confirmed. Organizations running browser-based AI agent tooling, RAG browsing agents, or Chromium-based automation frameworks (e.g., Puppeteer, Playwright, browser-use agents) that load untrusted web content could have agent sessions or extension-stored credentials/API keys exposed if this bypass is chained with extension-based credential storage, warranting patching before deploying browser automation in production agent pipelines.

Affected Systems

Google Chrome browser versions prior to 153.0.8010.36 on all platforms (Windows, macOS, Linux, ChromeOS); Chromium-based browsers and embedded Chromium instances (e.g., Electron apps, browser automation frameworks) that have not incorporated the corresponding upstream fix.

Indicators of Compromise

• No specific IOCs published (vulnerability disclosure, not an active campaign); monitor for crafted HTML pages targeting Chrome Extensions API prior to patch deployment.

Remediation Steps

1. 1

   Update Chrome

   Upgrade Google Chrome and all Chromium-based browsers/embedded instances to version 153.0.8010.36 or later immediately.

2. 2

   Patch automation frameworks

   Update any Chromium-based browser automation tools used by AI agents (Puppeteer, Playwright, Selenium-driven Chrome) to bundle the patched Chromium version.

3. 3

   Restrict extension privileges

   Audit and minimize installed browser extensions, especially those with elevated permissions, on systems used for agent-driven browsing or automation.

4. 4

   Sandbox untrusted content

   Ensure browser instances rendering untrusted or agent-fetched HTML operate in isolated, least-privilege environments separate from credential stores or API key vaults.

5. 5

   Verify vendor severity

   Cross-reference NVD CVSS score against Chromium's own security bulletin severity rating before prioritizing emergency response resources.