CVE-2004-0903: Stack-based buffer overflow in the writeGroup function in nsVCardObj.cpp for Mozilla Firefox before the Pre...

Security readout for executives and security teams

This is an old Mozilla-family mail handling flaw. A malicious vCard attachment could trigger a memory corruption bug when a message was previewed, potentially letting a remote attacker run code on the user’s machine. Modern exposure should be limited unless legacy Mozilla, Thunderbird, or Firefox-era components remain in use. Exposure is most plausible on unmanaged or legacy desktops, archived virtual machines, or embedded workstation images still running affected Mozilla-family clients. The provided affected-product metadata is incomplete, so validation should rely on actual installed versions and vendor advisories. Treat this as high priority only where legacy Mozilla-family software still exists. The business risk is endpoint compromise from a user previewing mail content, but normal modern environments should mainly need confirmation that affected clients are absent. Mitigation focus: Upgrade affected Mozilla-family clients using applicable vendor advisories.; Remove unsupported Mozilla, Thunderbird, or early Firefox builds from enterprise systems.; Block or quarantine unexpected vCard attachments where legacy clients remain..

Prepared

Jun 30, 2026, 02:43 UTC (UTC+00:00)

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