A mechanism that uses AppCache to hijack a URL in a domain using fallback by serving the files from a sub-path on the domain. This has been addressed by requiring fallback files be inside the manifest directory. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
http://www.securityfocus.com/bid/100242
http://www.securitytracker.com/id/1039124
https://access.redhat.com/errata/RHSA-2017:2456
https://access.redhat.com/errata/RHSA-2017:2534
https://bugzilla.mozilla.org/show_bug.cgi?id=1376459
https://security.gentoo.org/glsa/201803-14
https://www.debian.org/security/2017/dsa-3928
https://www.debian.org/security/2017/dsa-3968
https://www.mozilla.org/security/advisories/mfsa2017-18/
Source: MITRE
Published: 2018-06-11
Updated: 2019-10-03
Type: CWE-20
Base Score: 5.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N
Impact Score: 4.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 8.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Impact Score: 5.2
Exploitability Score: 2.8
Severity: HIGH