CVE-2015-4520

critical

Description

Mozilla Firefox before 41.0 and Firefox ESR 38.x before 38.3 allow remote attackers to bypass CORS preflight protection mechanisms by leveraging (1) duplicate cache-key generation or (2) retrieval of a value from an incorrect HTTP Access-Control-* response header.

References

https://euvd.enisa.europa.eu/vulnerability/EUVD-2015-4540

https://bugzilla.mozilla.org/show_bug.cgi?id=1200869

https://bugzilla.mozilla.org/show_bug.cgi?id=1200856

http://www.ubuntu.com/usn/USN-2754-1

http://www.ubuntu.com/usn/USN-2743-4

http://www.ubuntu.com/usn/USN-2743-3

http://www.ubuntu.com/usn/USN-2743-2

http://www.ubuntu.com/usn/USN-2743-1

http://www.securitytracker.com/id/1033640

http://www.securityfocus.com/bid/76816

http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html

http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

http://www.mozilla.org/security/announce/2015/mfsa2015-111.html

http://www.debian.org/security/2015/dsa-3365

http://rhn.redhat.com/errata/RHSA-2015-1852.html

http://rhn.redhat.com/errata/RHSA-2015-1834.html

http://lists.opensuse.org/opensuse-security-announce/2015-11/msg00025.html

http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00007.html

http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00005.html

http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00004.html

http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00003.html

http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00000.html

Details

Source: Mitre, NVD

Published: 2015-09-24

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: Critical

EPSS

EPSS: 0.00592