vulnerability
Red Hat: CVE-2021-43542: XMLHttpRequest error codes could have leaked the existence of an external protocol handler (Multiple Advisories)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 4 | (AV:N/AC:M/Au:N/C:P/I:N/A:N) | Dec 8, 2021 | Dec 9, 2021 | Aug 11, 2025 |
Severity
4
CVSS
(AV:N/AC:M/Au:N/C:P/I:N/A:N)
Published
Dec 8, 2021
Added
Dec 9, 2021
Modified
Aug 11, 2025
Description
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
Solutions
no-fix-redhat-rpm-packageredhat-upgrade-firefoxredhat-upgrade-firefox-debuginforedhat-upgrade-firefox-debugsourceredhat-upgrade-thunderbirdredhat-upgrade-thunderbird-debuginforedhat-upgrade-thunderbird-debugsource
NEW
Explore Exposure Command
Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.