CVE-2019-11747

The "Forget about this site" feature in the History pane is intended to remove all saved user data that indicates a user has visited a site. This includes removing any HTTP Strict Transport Security (HSTS) settings received from sites that use it. Due to a bug, sites on the pre-load list also have their HSTS setting removed. On the next visit to that site if the user specifies an http: URL rather than secure https: they will not be protected by the pre-loaded HSTS setting. After that visit the site's HSTS setting will be restored. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

• CWE-665

• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=1564481Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-25/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-26/Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=1564481Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-25/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-26/Vendor Advisory

Published

Sep 27, 2019

Last Modified

Jun 17, 2026

Status

Modified