CVE-2017-5384: Mozilla Firefox

Medium severity, CVSS 5.9. EPSS: 1.5% chance of exploitation in the next 30 days.

Proxy Auto-Config (PAC) files can specify a JavaScript function called for all URL requests with the full URL path which exposes more information than would be sent to the proxy itself in the case of HTTPS. Normally the Proxy Auto-Config file is specified by the user or machine owner and presumed to be non-malicious, but if a user has enabled Web Proxy Auto Detect (WPAD) this file can be served remotely. 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.