When pasting a <style> tag from the clipboard into a rich text editor, the CSS sanitizer does not escape < and > characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node’s innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.
[
{
"product": "Firefox ESR",
"vendor": "Mozilla",
"versions": [
{
"status": "affected",
"version": "before 68.4"
}
]
},
{
"product": "Firefox",
"vendor": "Mozilla",
"versions": [
{
"status": "affected",
"version": "before 72"
}
]
}
]
lists.opensuse.org/opensuse-security-announce/2020-01/msg00029.html
lists.opensuse.org/opensuse-security-announce/2020-01/msg00043.html
packetstormsecurity.com/files/155912/Slackware-Security-Advisory-mozilla-thunderbird-Updates.html
access.redhat.com/errata/RHSA-2020:0085
access.redhat.com/errata/RHSA-2020:0086
access.redhat.com/errata/RHSA-2020:0111
access.redhat.com/errata/RHSA-2020:0120
access.redhat.com/errata/RHSA-2020:0123
access.redhat.com/errata/RHSA-2020:0127
access.redhat.com/errata/RHSA-2020:0292
access.redhat.com/errata/RHSA-2020:0295
bugzilla.mozilla.org/show_bug.cgi?id=1602843
lists.debian.org/debian-lts-announce/2020/01/msg00005.html
lists.debian.org/debian-lts-announce/2020/01/msg00016.html
seclists.org/bugtraq/2020/Jan/12
seclists.org/bugtraq/2020/Jan/18
seclists.org/bugtraq/2020/Jan/26
security.gentoo.org/glsa/202003-02
usn.ubuntu.com/4234-1/
usn.ubuntu.com/4241-1/
usn.ubuntu.com/4335-1/
www.debian.org/security/2020/dsa-4600
www.debian.org/security/2020/dsa-4603
www.mozilla.org/security/advisories/mfsa2020-01/
www.mozilla.org/security/advisories/mfsa2020-02/