CVE-2017-5388: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 1.6% chance of exploitation in the next 30 days.

A STUN server in conjunction with a large number of "webkitRTCPeerConnection" objects can be used to send large STUN packets in a short period of time due to a lack of rate limiting being applied on e10s systems, allowing for a denial of service attack. This vulnerability affects Firefox < 51.

Affected products

  • Mozilla Firefox: before 51.0 (fixed in 51.0)

Published 2018-06-11. Last modified 2026-06-17.