CVE-2013-4200: The isURLInPortal method in the URLTool class in in_portal.py in Plone 2.1 through 4.1, 4.2.x through 4.2.5...

Security readout for executives and security teams

This Plone issue can let an attacker turn a legitimate site login flow into a redirect to another website. The main business risk is phishing against users who trust the Plone site. One referenced report also flags possible cookie forwarding in certain browsers, but the bundle does not prove active exploitation. Exposure is most likely where affected Plone sites expose standard login flows and rely on allow_external_login_sites to restrict post-login redirects. Internet-facing portals, intranets with trusted login links, and older unmaintained Plone deployments should be checked first. Prioritize remediation for internet-facing or user-trusted Plone sites. This is not presented as actively exploited in the bundle, but it can support convincing phishing through legitimate domains and should not remain open on authentication paths. Mitigation focus: Apply the Plone 20130618 hotfix referenced by Plone.; Upgrade or patch affected Plone branches using current vendor guidance.; Review allow_external_login_sites and login redirect configuration..

Prepared

Jun 14, 2026, 14:50 UTC (UTC+00:00)

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