CVE-2021-43844

/// Technical description

MSEdgeRedirect is a tool to redirect news, search, widgets, weather, and more to a user's default browser. MSEdgeRedirect versions before 0.5.0.1 are vulnerable to Remote Code Execution via specifically crafted URLs. This vulnerability requires user interaction and the acceptance of a prompt. With how MSEdgeRedirect is coded, parameters are impossible to pass to any launched file. However, there are two possible scenarios in which an attacker can do more than a minor annoyance. In Scenario 1 (confirmed), a user visits an attacker controlled webpage; the user is prompted with, and downloads, an executable payload; the user is prompted with, and accepts, the aforementioned crafted URL prompt; and RCE executes the payload the user previously downloaded, if the download path is successfully guessed. In Scenario 2 (not yet confirmed), a user visits an attacked controlled webpage; the user is prompted with, and accepts, the aforementioned crafted URL prompt; and a payload on a remote, attack

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References