USN-4234-1 fixed vulnerabilities in Firefox. The update introduced various
minor regressions. This update fixes the problems.
We apologize for the inconvenience.
Original advisory details:
Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information, bypass Content Security Policy (CSP) restrictions, conduct
cross-site scripting (XSS) attacks, or execute arbitrary code.
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.
Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.firefox.com in that process and forcing a log-in to a malicious Firefox Sync account. Preference settings that disable the sandbox are then synchronized to the local machine and the compromised browser would restart without the sandbox if a crash is triggered. This vulnerability affects Firefox ESR < 60.9, Firefox ESR < 68.1, and Firefox < 69.
Mozilla developers reported memory safety bugs present in Firefox 71. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 72.
Mozilla developers reported memory safety bugs present in Firefox 71 and Firefox ESR 68.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.
After a HelloRetryRequest has been sent, the client may negotiate a lower protocol that TLS 1.3, resulting in an invalid state transition in the TLS State Machine. If the client gets into this state, incoming Application Data records will be ignored. This vulnerability affects 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.
If an XML file is served with a Content Security Policy and the XML file includes an XSL stylesheet, the Content Security Policy will not be applied to the contents of the XSL stylesheet. If the XSL sheet e.g. includes JavaScript, it would bypass any of the restrictions of the Content Security Policy applied to the XML document. This vulnerability affects Firefox < 72.
Due to a missing case handling object types, a type confusion vulnerability could occur, resulting in a crash. We presume that with enough effort that it could be exploited to run arbitrary code. 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 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.
If an image had not loaded correctly (such as when it is not actually an image), it could be dragged and dropped cross-domain, resulting in a cross-origin information leak. This vulnerability affects Firefox < 71.
Mozilla developers reported memory safety bugs present in Firefox 70. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 71.
Mozilla developers reported memory safety bugs present in Firefox 70 and Firefox ESR 68.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
Under certain conditions, when retrieving a document from a DocShell in the antitracking code, a race condition could cause a use-after-free condition and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
Under certain conditions, when checking the Resist Fingerprinting preference during device orientation checks, a race condition could have caused a use-after-free and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
When using nested workers, a use-after-free could occur during worker destruction. This resulted in a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
The plain text serializer used a fixed-size array for the number of <ol> elements it could process; however it was possible to overflow the static-sized array leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
If upgrade-insecure-requests was specified in the Content Security Policy, and a link was dragged and dropped from that page, the link was not upgraded to https. This vulnerability affects Firefox < 70.
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.
A compromised content process could send a message to the parent process that would cause the 'Click to Play' permission prompt to be shown. However, due to lack of validation from the parent process, if the user accepted the permission request an attacker-controlled permission would be granted rather than the 'Click to Play' permission. This vulnerability affects Firefox < 70.