Summary
Heym contains an improper authorization vulnerability that allows shared collaborators to change a workflow's error-handling workflow reference. When the parent workflow fails, the substituted workflow may receive decrypted owner credentials, allowing an attacker to exfiltrate sensitive secrets.
Heym contains an improper authorization vulnerability that allows shared collaborators to change a workflow's error-handling workflow reference. When the parent workflow fails, the substituted workflow may receive decrypted owner credentials, allowing an attacker to exfiltrate sensitive secrets.
Affected context
The issue affects Heym workflow deployments where shared collaborators can edit workflows and the error_workflow_id field is not restricted to workflow owners. Risk arises when an attacker-controlled error workflow can execute as part of an owner's workflow failure path and access credentials made available to that execution context.
The issue affects Heym workflow deployments where shared collaborators can edit workflows and the error_workflow_id field is not restricted to workflow owners. Risk arises when an attacker-controlled error workflow can execute as part of an owner's workflow failure path and access credentials made available to that execution context.
Exploit preconditions
- Attack surface: Workflow configuration and error-handling workflow selection
- Required access: Shared collaborator permissions sufficient to modify an affected workflow field
- Trigger point: Execution of the parent workflow when it enters an error path
- Why exploitation is possible: The
error_workflow_idfield is omitted from owner-only execution controls, allowing a collaborator to redirect error handling to a workflow they control
- Attack surface: Workflow configuration and error-handling workflow selection
- Required access: Shared collaborator permissions sufficient to modify an affected workflow field
- Trigger point: Execution of the parent workflow when it enters an error path
- Why exploitation is possible: The
error_workflow_idfield is omitted from owner-only execution controls, allowing a collaborator to redirect error handling to a workflow they control
Why this happens
The vulnerability results from an incomplete authorization policy that fails to classify error_workflow_id as an owner-restricted field. This allows a lower-privileged collaborator to alter a security-sensitive workflow relationship and influence execution performed with the owner's credential context. The behavior maps to CWE-863: Incorrect Authorization, because access control does not consistently enforce the intended privilege boundary.
The vulnerability results from an incomplete authorization policy that fails to classify error_workflow_id as an owner-restricted field. This allows a lower-privileged collaborator to alter a security-sensitive workflow relationship and influence execution performed with the owner's credential context. The behavior maps to CWE-863: Incorrect Authorization, because access control does not consistently enforce the intended privilege boundary.
Potential impact
- An attacker may redirect failure handling to a workflow they control
- Owner-associated decrypted credentials could be exposed or exfiltrated
- Sensitive integrations and connected services could be accessed
- Workflow integrity and confidentiality could be compromised
- The issue could enable further privilege escalation within the Heym deployment
- An attacker may redirect failure handling to a workflow they control
- Owner-associated decrypted credentials could be exposed or exfiltrated
- Sensitive integrations and connected services could be accessed
- Workflow integrity and confidentiality could be compromised
- The issue could enable further privilege escalation within the Heym deployment
General mitigation guidance
Mitigation generally focuses on enforcing authorization consistently across all workflow relationship and execution-control fields.
Defensive patterns include:
- Treating error-handler references and similar execution hooks as owner-restricted by default
- Applying server-side authorization checks rather than relying only on client-side field filtering
- Preventing lower-privileged workflows from inheriting or accessing owner credential contexts
- Using scoped, least-privilege credentials for workflow execution
- Separating failure handling from sensitive credential-bearing execution paths
- Revalidating workflow ownership and permissions whenever referenced workflows are resolved
Mitigation generally focuses on enforcing authorization consistently across all workflow relationship and execution-control fields.
Defensive patterns include:
- Treating error-handler references and similar execution hooks as owner-restricted by default
- Applying server-side authorization checks rather than relying only on client-side field filtering
- Preventing lower-privileged workflows from inheriting or accessing owner credential contexts
- Using scoped, least-privilege credentials for workflow execution
- Separating failure handling from sensitive credential-bearing execution paths
- Revalidating workflow ownership and permissions whenever referenced workflows are resolved
How teams detect issues like this
Detection approaches may include:
- Static analysis and policy checks for authorization allowlists that omit workflow linkage fields
- Code review searches for collaborator-editable fields that influence execution control flow
- Tests verifying that shared collaborators cannot modify error handlers or equivalent callback references
- Audit logging and alerting for changes to workflow relationships and credential access contexts
- Automated security review tools that identify missing authorization checks on sensitive object properties
Detection approaches may include:
- Static analysis and policy checks for authorization allowlists that omit workflow linkage fields
- Code review searches for collaborator-editable fields that influence execution control flow
- Tests verifying that shared collaborators cannot modify error handlers or equivalent callback references
- Audit logging and alerting for changes to workflow relationships and credential access contexts
- Automated security review tools that identify missing authorization checks on sensitive object properties
