CVE-2021-33510: Plone through 5.2.4 allows remote authenticated managers to conduct SSRF attacks via an event ical URL, to...

Security readout for executives and security teams

Plone sites through 5.2.4 had a flaw where an authenticated user with Manager privileges could misuse an event iCal URL to make the server fetch unintended resources and read one line from a file. This is not described as unauthenticated compromise, but it can expose sensitive internal data if privileged accounts are abused. Exposure is most likely on Plone deployments at or below 5.2.4 where users hold Manager privileges and can configure or interact with event iCal URLs. Public internet exposure increases business risk, but the cited sources identify authenticated Manager access as a prerequisite. Prioritize remediation for internet-facing Plone systems and environments where Manager accounts are shared, stale, or weakly protected. The issue is constrained by authentication and role requirements, but privileged SSRF and file-read exposure can still affect secrets, internal services, or operational trust. Mitigation focus: Apply the Plone 20210518 security hotfix referenced by the vendor.; Check Plone vendor guidance for supported upgrades beyond affected versions.; Review and reduce users with Manager privileges where not required..

Prepared

Jun 3, 2026, 02:27 UTC (UTC+00:00)

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