Summary
A broken object-level authorization flaw in Plane's bulk asset endpoint allows a workspace Guest to reference assets belonging to another project in the same workspace. If the attacker knows valid asset identifiers and can control a destination entity, they may reassign the assets and obtain presigned download URLs for files they should not access.
A broken object-level authorization flaw in Plane's bulk asset endpoint allows a workspace Guest to reference assets belonging to another project in the same workspace. If the attacker knows valid asset identifiers and can control a destination entity, they may reassign the assets and obtain presigned download URLs for files they should not access.
Affected context
The issue occurs in Plane deployments where the bulk asset endpoint processes asset identifiers together with a workspace slug and project identifier from the request path. The asset lookup verifies workspace membership but does not sufficiently bind each asset to the project identified by the URL, allowing cross-project references within the same workspace under conditions where a Guest can submit the request.
The issue occurs in Plane deployments where the bulk asset endpoint processes asset identifiers together with a workspace slug and project identifier from the request path. The asset lookup verifies workspace membership but does not sufficiently bind each asset to the project identified by the URL, allowing cross-project references within the same workspace under conditions where a Guest can submit the request.
Exploit preconditions
- Attack surface: Plane's bulk asset management API
- Required access: Workspace Guest access and the ability to submit requests
- Required knowledge: Valid asset UUIDs belonging to another project in the same workspace
- Trigger point: Bulk asset processing when asset ownership or related entity identifiers are updated
- Why exploitation is possible: The asset query filters by workspace and supplied asset IDs but does not enforce the project boundary from the request URL
- Attack surface: Plane's bulk asset management API
- Required access: Workspace Guest access and the ability to submit requests
- Required knowledge: Valid asset UUIDs belonging to another project in the same workspace
- Trigger point: Bulk asset processing when asset ownership or related entity identifiers are updated
- Why exploitation is possible: The asset query filters by workspace and supplied asset IDs but does not enforce the project boundary from the request URL
Why this happens
The endpoint performs an object lookup using identifiers and workspace scope without consistently applying the project-level authorization context. This creates an authorization gap in which possession of a valid object identifier can substitute for permission to access or modify that object. The behavior maps to CWE-639, Authorization Bypass Through User-Controlled Key, because user-controlled identifiers influence object selection without an adequate ownership or relationship check.
The endpoint performs an object lookup using identifiers and workspace scope without consistently applying the project-level authorization context. This creates an authorization gap in which possession of a valid object identifier can substitute for permission to access or modify that object. The behavior maps to CWE-639, Authorization Bypass Through User-Controlled Key, because user-controlled identifiers influence object selection without an adequate ownership or relationship check.
Potential impact
- An attacker may reassign assets owned by another project within the same workspace.
- An attacker could associate hijacked files with issues, comments, pages, drafts, or projects they control.
- Plane may generate presigned download URLs for files outside the attacker's authorized project.
- Confidential project attachments could be disclosed.
- Asset relationships and project data could be altered or disrupted.
- An attacker may reassign assets owned by another project within the same workspace.
- An attacker could associate hijacked files with issues, comments, pages, drafts, or projects they control.
- Plane may generate presigned download URLs for files outside the attacker's authorized project.
- Confidential project attachments could be disclosed.
- Asset relationships and project data could be altered or disrupted.
General mitigation guidance
Mitigation generally centers on enforcing authorization at the object and
relationship level rather than relying only on workspace membership or
user-supplied identifiers.
Common defensive patterns include:
- Scope asset queries by the authenticated user's permitted project relationships.
- Enforce that every asset belongs to the project represented by the request context before allowing updates.
- Recheck authorization immediately before generating presigned download URLs.
- Avoid treating client-supplied project or entity identifiers as proof of ownership.
- Apply least-privilege permissions to Guest roles and separate read, update, and reassignment capabilities.
- Use centralized, deny-by-default authorization policies consistently across asset endpoints.
Mitigation generally centers on enforcing authorization at the object and
relationship level rather than relying only on workspace membership or
user-supplied identifiers.
Common defensive patterns include:
- Scope asset queries by the authenticated user's permitted project relationships.
- Enforce that every asset belongs to the project represented by the request context before allowing updates.
- Recheck authorization immediately before generating presigned download URLs.
- Avoid treating client-supplied project or entity identifiers as proof of ownership.
- Apply least-privilege permissions to Guest roles and separate read, update, and reassignment capabilities.
- Use centralized, deny-by-default authorization policies consistently across asset endpoints.
How teams detect issues like this
Organizations can look for this class of issue through:
- Static and semantic analysis that identifies database queries using user-controlled IDs without tenant or project scoping.
- Code review checks for authorization decisions performed only at workspace level.
- Tests that attempt cross-project object access using identifiers from sibling projects.
- API monitoring for Guests submitting asset IDs that do not belong to the project in the request context.
- Policy enforcement requiring object-level authorization checks before mutations and signed URL generation.
Automated security review tools may help flag identifier-based lookups that lack corresponding ownership checks.
Organizations can look for this class of issue through:
- Static and semantic analysis that identifies database queries using user-controlled IDs without tenant or project scoping.
- Code review checks for authorization decisions performed only at workspace level.
- Tests that attempt cross-project object access using identifiers from sibling projects.
- API monitoring for Guests submitting asset IDs that do not belong to the project in the request context.
- Policy enforcement requiring object-level authorization checks before mutations and signed URL generation.
Automated security review tools may help flag identifier-based lookups that lack corresponding ownership checks.
