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.
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.
Security update for MozillaFirefox
Mozilla: Bypass of @namespace CSS sanitization during pasting Mozilla: Type Confusion in XPCVariant.cpp Mozilla: CSS sanitization does not escape HTML tags Mozilla: Memory safety bugs fixed in Firefox 72 and Firefox ESR 68.4 Mozilla: IonMonkey type confusion with StoreElementHole and FallibleStoreElement
Security update for MozillaFirefox
Affected: Ubuntu:16.04:LTS: firefox, Ubuntu:16.04:LTS: thunderbird, Ubuntu:18.04:LTS: firefox, Ubuntu:18.04:LTS: thunderbird, Ubuntu:18.04:LTS: mozjs52, Ubuntu:18.04:LTS: mozjs38, Ubuntu:20.04:LTS: firefox, Ubuntu:20.04:LTS: thunderbird, Ubuntu:20.04:LTS: mozjs52
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.