Summary
Ghost exposed the secret tokens associated with pending staff invitations to users who could view staff invites. A staff user could use a higher-privilege invitation token to accept that invite and potentially escalate their privileges.
Ghost exposed the secret tokens associated with pending staff invitations to users who could view staff invites. A staff user could use a higher-privilege invitation token to accept that invite and potentially escalate their privileges.
Affected context
The issue affects Ghost deployments using versions from 4.39.0 through 6.63.0 where staff users can view pending invitations. The risk exists when invitation details disclose tokens without adequately limiting visibility according to the privileges associated with each invitation.
The issue affects Ghost deployments using versions from 4.39.0 through 6.63.0 where staff users can view pending invitations. The risk exists when invitation details disclose tokens without adequately limiting visibility according to the privileges associated with each invitation.
Exploit preconditions
- Attack surface: Ghost's staff invitation viewing functionality
- Required access: An authenticated staff account with permission to view staff invites
- Trigger point: Viewing pending invitations and obtaining a secret invitation token
- Why exploitation is possible: Invitation tokens for higher-privilege roles may be exposed to lower-privileged staff users, allowing those users to accept an invitation intended to grant elevated access
- Attack surface: Ghost's staff invitation viewing functionality
- Required access: An authenticated staff account with permission to view staff invites
- Trigger point: Viewing pending invitations and obtaining a secret invitation token
- Why exploitation is possible: Invitation tokens for higher-privilege roles may be exposed to lower-privileged staff users, allowing those users to accept an invitation intended to grant elevated access
Why this happens
The underlying issue is an information disclosure caused by insufficient authorization-aware handling of sensitive invitation data. The application makes secret tokens observable to users who may be allowed to view invitation records but are not authorized to access tokens for invitations granting greater privileges. This behavior maps primarily to CWE-203: Observable Discrepancy, with characteristics related to CWE-943: Improper Neutralization of Special Elements in Data Query Logic where data exposure is enabled by inadequate separation of sensitive fields and access rules.
The underlying issue is an information disclosure caused by insufficient authorization-aware handling of sensitive invitation data. The application makes secret tokens observable to users who may be allowed to view invitation records but are not authorized to access tokens for invitations granting greater privileges. This behavior maps primarily to CWE-203: Observable Discrepancy, with characteristics related to CWE-943: Improper Neutralization of Special Elements in Data Query Logic where data exposure is enabled by inadequate separation of sensitive fields and access rules.
Potential impact
- A staff user may accept an invitation with greater privileges than their current role
- Unauthorized administrative access could occur
- Sensitive content and management functions could become accessible
- The affected account or tenant could be altered by an escalated user
- A staff user may accept an invitation with greater privileges than their current role
- Unauthorized administrative access could occur
- Sensitive content and management functions could become accessible
- The affected account or tenant could be altered by an escalated user
General mitigation guidance
Mitigation generally focuses on minimizing exposure of invitation secrets and enforcing authorization at the field and action level.
Common defensive patterns include:
- Never returning invitation tokens in staff-facing listings or interfaces
- Applying role-aware authorization before exposing sensitive invitation attributes
- Separating invitation metadata from secret acceptance credentials
- Binding invitation acceptance to the intended recipient or an independently verified identity where practical
- Limiting administrative privileges and reviewing existing invitation and staff-account permissions
- Expiring, revoking, or rotating invitation tokens after suspected disclosure
These controls reduce the chance that a user with ordinary staff visibility can obtain or misuse a higher-privilege credential.
Mitigation generally focuses on minimizing exposure of invitation secrets and enforcing authorization at the field and action level.
Common defensive patterns include:
- Never returning invitation tokens in staff-facing listings or interfaces
- Applying role-aware authorization before exposing sensitive invitation attributes
- Separating invitation metadata from secret acceptance credentials
- Binding invitation acceptance to the intended recipient or an independently verified identity where practical
- Limiting administrative privileges and reviewing existing invitation and staff-account permissions
- Expiring, revoking, or rotating invitation tokens after suspected disclosure
These controls reduce the chance that a user with ordinary staff visibility can obtain or misuse a higher-privilege credential.
How teams detect issues like this
Organizations can look for this class of issue through:
- Static analysis and code review checks for secret tokens included in list or detail responses
- Authorization tests comparing visibility of invitation metadata across staff roles
- API and UI testing that verifies higher-privilege invitation secrets remain inaccessible
- Audit monitoring for invitation acceptance, role changes, and unexpected privilege increases
- Policy enforcement that classifies invitation tokens as credentials and prohibits their exposure in general administrative views
Automated security testing and code review tools may help identify sensitive-field exposure and missing object-level authorization checks.
Organizations can look for this class of issue through:
- Static analysis and code review checks for secret tokens included in list or detail responses
- Authorization tests comparing visibility of invitation metadata across staff roles
- API and UI testing that verifies higher-privilege invitation secrets remain inaccessible
- Audit monitoring for invitation acceptance, role changes, and unexpected privilege increases
- Policy enforcement that classifies invitation tokens as credentials and prohibits their exposure in general administrative views
Automated security testing and code review tools may help identify sensitive-field exposure and missing object-level authorization checks.
