Mozilla developers and community members Andreea Pavel, Christian Holler, Honza Bambas, Jason Kratzer, and Jeff Gilbert reported memory safety bugs present in Firefox 67 and Firefox ESR 60.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.
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.
Empty or malformed p256-ECDH public keys may trigger a segmentation fault due values being improperly sanitized before being copied into memory and used.
A use-after-free vulnerability can occur in HTTP/2 when a cached HTTP/2 stream is closed while still in use, resulting in a potentially exploitable crash.
POST requests made by NPAPI plugins, such as Flash, that receive a status 308 redirect response can bypass CORS requirements. This can allow an attacker to perform Cross-Site Request Forgery (CSRF) attacks.
When an inner window is reused, it does not consider the use of document.domain for cross-origin protections. If pages on different subdomains ever cooperatively use document.domain, then either page can abuse this to inject script into arbitrary pages on the other subdomain, even those that did not use document.domain to relax their origin security.
As part of his winning Pwn2Own entry, Niklas Baumstark demonstrated a sandbox escape by installing a malicious language pack and then opening a browser feature that used the compromised translation.