If an existing cookie is changed to be "HttpOnly" while a document is open, the original value remains accessible through script until that document is closed. Network requests correctly use the changed HttpOnly cookie. This vulnerability affects Firefox < 58.
http://www.securityfocus.com/bid/102786
http://www.securitytracker.com/id/1040270
https://bugzilla.mozilla.org/show_bug.cgi?id=1421324
Source: MITRE
Published: 2018-06-11
Updated: 2018-06-25
Type: CWE-200
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 5.3
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Impact Score: 1.4
Exploitability Score: 3.9
Severity: MEDIUM