Rapid7

vulnerability

Arch Linux: Information disclosure (CVE-2021-43542)

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:P/I:N/A:N)
Published
Dec 8, 2021
Added
Jul 11, 2025
Modified
Mar 25, 2026

Description

A security issue has been found in Firefox before version 95 and Thunderbird before version 91.4.0. Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.

Solution

arch-linux-upgrade-latest

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.