Zhayujie CowAgent Browser Tool Information Disclosure Vulnerability

An information disclosure vulnerability has been identified in Zhayujie CowAgent versions through 2.1.0. The issue arises in the Browser Tool component, specifically within the function BrowserTool._do_navigate in the file agent/tools/browser/browser_tool.py. This vulnerability allows an authenticated user to manipulate the tool into navigating to a local file via a file:// URL, effectively exfiltrating its contents. The flaw occurs because the tool does not properly validate URL schemes before forwarding them to the Playwright browser automation library, bypassing the intended trust boundary and transforming a feature meant for web navigation into a local file reader.

Impact

Exploitation of this vulnerability could lead to unauthorized access to local files, including sensitive information such as configuration files, cached credentials, API keys, and other data accessible by the CowAgent process user.

Reproduction

To reproduce this vulnerability, an authenticated user must invoke the Browser Tool's navigation function with a file:// URL pointing to a readable local file. The tool will then load the file through Playwright, extract its contents via a snapshot feature, and return the data, effectively disclosing the file's information.

Remediation

Users are advised to update to Zhayujie CowAgent version 2.1.3, where this vulnerability has been addressed.