Problem accepting self-signed SSL certificates on FF3
Summary: PortSwigger Research reports that Firefox 3's documented handling of invalid SSL certificates fails for many users, who see an error dialog with no option to add an exception when the browser receives a proxy's self-signed certificate. The workaround is to set network.dns.disableIPv6 to true in about:config, after which Firefox shows a different error message with a working "add an exception" link.
What you should know: Testers using an intercepting proxy such as Burp cannot reach HTTPS sites through it until they find this undocumented about:config change, and the article notes several users gave up and switched browsers instead.
Read the original at PortSwigger Research ↗
- Topics
- Vulnerabilities & Patching
- Related
- Attackers Exploit UnrealIRCd Flaw That Enables Server-Level Command Injection Cyber Risks · Nov 14, 2026U.S. CISA adds Check Point and UnrealIRCd flaws to its Known Exploited Vulnerabilities catalog Cyber Risks · Nov 14, 2026PostgreSQL Patches 52 Flaws, Including 22-Year-Old Bug Enabling Authenticated RCE Cyber Risks · Nov 13, 2026