CVE-2005-0147: Firefox before 1.0 and Mozilla before 1.7.5, when configured to use a proxy, respond to 407 proxy auth requ...

Security readout for executives and security teams

This is a legacy browser credential-leak issue. Firefox before 1.0 and Mozilla before 1.7.5 could answer proxy-authentication challenges from arbitrary servers when proxy use was configured, potentially exposing NTLM or SPNEGO credentials to a remote attacker. Likely exposure is limited to legacy systems still running the named browser versions with proxy authentication enabled. Modern managed endpoints are unlikely to be affected unless old images, kiosks, lab systems, or unsupported embedded desktops remain in service. Treat this as a targeted legacy-risk cleanup item. It is not reported as actively exploited, but affected systems could leak reusable enterprise credentials. Prioritize if old browsers remain on domain-joined or proxy-authenticated endpoints. Mitigation focus: Remove or upgrade Firefox before 1.0 and Mozilla before 1.7.5.; Apply relevant vendor or distribution advisories, including Red Hat guidance where applicable.; Disable NTLM or SPNEGO proxy authentication for unsupported legacy browsers..

Prepared

Jun 30, 2026, 01:23 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.