A Content-Security-Policy that blocks in-line scripts could be bypassed using an object tag to execute JavaScript in the protected document (cross-site scripting). This is a separate bypass from CVE-2019-17000.*Note: This flaw only affected Firefox 69 and was not present in earlier versions.*. This vulnerability affects Firefox < 70.
When pasting a <style> tag from the clipboard into a rich text editor, the CSS sanitizer incorrectly rewrites a @namespace rule. This could allow for injection into certain types of websites resulting in data exfiltration. 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.
An object tag with a data URI did not correctly inherit the document's Content Security Policy. This allowed a CSP bypass in a cross-origin frame if the document's policy explicitly allowed data: URIs. This vulnerability affects Firefox < 70.
Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters - enabling the use of entities to mask the actual characters of interest from filters. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
A compromised sandboxed content process can perform a Universal Cross-site Scripting (UXSS) attack on content from any site it can cause to be loaded in the same process. Because addons.mozilla.org and accounts.firefox.com have close ties to the Firefox product, malicious manipulation of these sites within the browser can potentially be used to modify a user's Firefox configuration. These two sites will now be isolated into their own process and not allowed to be loaded in a standard content process. This vulnerability affects Firefox < 69.
Some HTML elements, such as <title> and <textarea>, can contain literal angle brackets without treating them as markup. It is possible to pass a literal closing tag to .innerHTML on these elements, and subsequent content after that will be parsed as if it were outside the tag. This can lead to XSS if a site does not filter user input as strictly for these elements as it does for other elements. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.
The default webcal: protocol handler will load a web site vulnerable to cross-site scripting (XSS) attacks. This default was left in place as a legacy feature and has now been removed. *Note: this issue only affects users with an account on the vulnerable service. Other users are unaffected.*. This vulnerability affects Firefox < 67.
Due to an error while parsing page content, it is possible for properly sanitized user input to be misinterpreted and lead to XSS hazards on web sites in certain circumstances. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.
Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of triggering parsing errors. This allows malicious code to then be processed, evading cross-site scripting (XSS) filtering. This vulnerability affects Firefox < 68.