Endpoint Vulnerability

Use-after-free in service workers with nested sync events

Description

Security researcher Looben Yang discovered a use-after-free vulnerability when working with nested sync event loops in Service Workers. He discovered a mechanism where scripts can close their own worker, which will then trigger a synchronization XMLHttpRequest on this now closed and released worker. This results in a potentially exploitable crash when triggered.

Affected Products

Firefox

References

CVE-2016-5259,