How the CVE Works
The vulnerability arises when KeystoneJS processes `update` and `delete` mutations with multiple unique filters in the `where` clause. Despite `isFilterable` or `defaultIsFilterable` restrictions, the system incorrectly evaluates combined filters (e.g., `id` + email), allowing attackers to infer restricted field values. For example, if `email` is not filterable, an attacker can still probe its existence by pairing it with a valid `id` in a mutation. Successful execution confirms the email’s presence, effectively bypassing access controls. This flaw stems from incomplete validation in mutation operations, whereas `findMany` queries correctly enforce filtering restrictions.
DailyCVE Form
Platform: KeystoneJS
Version: <6.5.0
Vulnerability: Filter bypass
Severity: Medium
Date: 2023-XX-XX
What Undercode Say:
Exploitation:
- Probing Fields: Craft a GraphQL mutation with multiple unique filters (e.g.,
where: { id: "1", email: "[email protected]" }). - Oracle Technique: Observe mutation success/failure to deduce restricted field values.
- Automation: Script repeated mutations to enumerate sensitive data.
Example Attack Query:
mutation {
updateUser(where: { id: "1", email: "[email protected]" }, data: { name: "hacked" }) {
id
}
}
Protection:
1. Patch: Upgrade to `@keystone-6/[email protected]`.
2. Workaround Code:
// Disable filtering on sensitive fields
User: list({
fields: {
email: text({ isFilterable: false }),
},
defaultIsFilterable: false,
})
3. Schema Hardening:
// Omit fields from GraphQL reads
email: text({ graphql: { omit: { read: true } } })
4. Access Control:
// Disable mutations entirely
access: { operation: { update: false, delete: false } }
Detection Commands:
- Audit Dependencies:
npm list @keystone-6/core
- Log Suspicious Mutations: Monitor GraphQL logs for multi-filter
update/deleteoperations.
Mitigation Script:
// Pre-mutation hook to validate filters
hooks: {
validateInput: ({ resolvedData, context }) => {
if (Object.keys(resolvedData.where).length > 1) throw new Error("Filter bypass attempt");
},
}
References:
- KeystoneJS 6.5.0 Changelog
- GraphQL Security Best Practices
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
