Craft CMS 5.0.0 through 5.10.12 (fixed in 5.10.13) contains a broken access control flaw in the nested-elements reorder endpoint. When an authenticated control panel user with viewEntries and viewPeerEntries (but without savePeerEntries) opens another author's entry in read-only mode, Craft unconditionally grants that session a `manageNestedElements::<ownerId>::field:<handle>` authorization flag for the entry's Matrix/Address fields. Unlike the corresponding delete endpoint, actions/nested-elements/reorder trusts this session flag alone and never rechecks the caller's save permission for the owner element. As a result, a view-only user can POST to actions/nested-elements/reorder using the ownerElementType, ownerId, ownerSiteId, attribute, elementIds, and offset parameters present in the read-only page source and rewrite the sort order of Matrix blocks or Addresses belonging to content they are explicitly denied save access to.
CVSS Details
- CVSS 4.0 Base Score: 5.3 (MEDIUM)
- CVSS 4.0 Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
- CVSS 3.1 Base Score: 4.3
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub