By using a form with a data URI it was possible to gain access to the privileged JSONView object that had been cloned into content. Impact from exposing this object appears to be minimal, however it was a bypass of existing defense in depth mechanisms. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Link | Tags |
|---|---|
| https://www.mozilla.org/security/advisories/mfsa2019-35/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2019-33/ | vendor advisory |
| https://www.mozilla.org/security/advisories/mfsa2019-34/ | vendor advisory |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1561502 | issue tracking permissions required |
| https://security.gentoo.org/glsa/202003-10 | vendor advisory third party advisory |
| https://usn.ubuntu.com/4335-1/ | vendor advisory third party advisory |