Improved Host Header Security in Mozilla Geckodriver

CVE-2021-4138

What is CVE-2021-4138?

This vulnerability arises from inadequate validation of Host headers in Mozilla Geckodriver. It allows attackers to make requests using malicious host headers, potentially exposing the application to security risks. To mitigate this, Mozilla has improved host header checks to reject requests that are not directed to a known local hostname or IP address, or the hostname specified by the server.

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