Auth bypass in Mozilla Firefox

CVE-2018-18505

An earlier fix for an Inter-process Communication (IPC) vulnerability, CVE-2011-3079, added authentication to communication between IPC endpoints and server parents during IPC process creation. This authentication is insufficient for channels created after the IPC process is started, leading to the authentication not being correctly applied to later channels. This could allow for a sandbox escape through IPC channels due to lack of message validation in the listener process. This vulnerability affects Thunderbird < 60.5, Firefox ESR < 60.5, and Firefox < 65.

Vulnerability class: Broken Authentication

EPSS: 0.045 (90.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2018-18505?
CVE-2018-18505 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Authentication. CVSS score: 10.0/10. Published 2019-02-05.
How severe is CVE-2018-18505?
Critical severity. CVSS v3 base score is 10.0 out of 10.