Advisory Details

This vulnerability allows network adjacent attackers to execute arbitrary code on vulnerable installations of Xiaomi Mi6 Browser. User interaction is required to exploit this vulnerability in that the target must connect to a malicious access point.

The specific flaw exists within the handling of intents. A crafted intent can cause the Captive Portal to to open a browser to a specified location without user interaction. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current process.

This vulnerability is being disclosed publicly without a patch in accordance with the ZDI 120 day deadline.

11/14/18 - ZDI reported vulnerability to vendor
11/14/18 - Vendor acknowledged
01/27/19 - ZDI contacted vendor requesting a status update
02/06/19 - ZDI contacted vendor again requesting a status update
02/06/19 - Vendor replied stating they plan to publish an update by the end of February
02/08/19 - ZDI notified the vendor the case would be 0-dayed if a fix was not available by the end of February
03/04/19 - Vendor replied but did not provide ETA
03/06/19 - ZDI notified the vendor the intention to 0-day the reports

-- Mitigation:
Given the nature of the vulnerability the only salient mitigation strategy is to restrict interaction with the application to trusted files.

• 2018-11-15 - Vulnerability reported to vendor
• 2019-03-15 - Coordinated public release of advisory
• 2020-01-15 - Advisory Updated