CVE-2026-27803

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Vaultwarden ausnutzen, um Sicherheitsmaßnahmen zu umgehen, erweiterte Privilegien zu erlangen, vertrauliche Informationen offenzulegen und Daten zu manipulieren.

## Summary Testing confirmed that even when a Manager has `manage=false` for a given collection, they can still perform the following management operations as long as they have access to the collection: * `PUT /api/organizations/<org_id>/collections/<col_id>` succeeds (HTTP 200) * `PUT /api/organizations/<org_id>/collections/<col_id>/users` succeeds (HTTP 200) * `DELETE /api/organizations/<org_id>/collections/<col_id>` succeeds (HTTP 200) ## Description * The Manager guard checks only whether the user **can access the collection**, not whether they have `manage` privileges. This check is directly applied to management endpoints. src/auth.rs:816 ```rust if !Collection::can_access_collection(&headers.membership, &col_id, &conn).await { err_handler!("The current user isn't a manager for this collection") } ``` * The `can_access_collection` function does **not** evaluate the `manage` flag. src/db/models/collection.rs:140 ```rust pub async fn can_access_collection(member: &Membership, col_id: &CollectionId, conn: &DbConn) -> bool { member.has_status(MembershipStatus::Confirmed) && (member.has_full_access() || CollectionUser::has_access_to_collection_by_user(col_id, &member.user_uuid, conn).await || ... ``` * A separate management-permission check exists and includes `manage` validation, but it is **not used** during authorization for the affected endpoints. src/db/models/collection.rs:516 ```rust pub async fn is_manageable_by_user(&self, user_uuid: &UserId, conn: &DbConn) -> bool { let Some(member) = Membership::find_confirmed_by_user_and_org(user_uuid, &self.org_uuid, conn).await else { return false; }; if member.has_full_access() { return true; } ... ``` * The actual update and deletion endpoints only accept `ManagerHeaders` and do not perform additional `manage` checks. src/api/core/organizations.rs:608 ```rust async fn put_organization_collection_update(..., headers: ManagerHeaders, ...) ``` src/api/core/organizations.rs:890 ```rust async fn put_collection_users(..., headers: ManagerHeaders, ...) ``` src/api/core/organizations.rs:747 ```rust async fn delete_organization_collection(..., headers: ManagerHeaders, ...) ``` ## Preconditions * The attacker is a **Manager** within the target organization. * The attacker has access to the target collection (`assigned=true`). * The attacker’s permission for that collection is `manage=false`. * A valid API access token has been obtained. ## Steps to Reproduce 1. Confirm that the attacker’s current permissions for the target collection include `manage=false`. <img width="2015" height="636" alt="image" src="https://github.com/user-attachments/assets/58ddc733-e37c-4766-a980-b1ea1918ceb4" /> 2. As a control test, verify that update operations fail for collections the attacker cannot access. <img width="2021" height="852" alt="image" src="https://github.com/user-attachments/assets/d8699442-2dfc-4d73-8940-ec10f4a175f0" /> 3. Confirm that update operations succeed for the target collection where `manage=false`. <img width="2013" height="690" alt="image" src="https://github.com/user-attachments/assets/33d9845d-d18e-456c-a58c-e780911347a9" /> 4. Use `PUT /collections/{col_id}/users` to set `manage=true`, confirming that the attacker can escalate their own privileges. <img width="2018" height="488" alt="image" src="https://github.com/user-attachments/assets/da8c5246-cf2a-46c2-9a25-e99d907f852d" /> 5. Verify that deletion of the collection succeeds despite the Manager lacking management rights. <img width="2018" height="487" alt="image" src="https://github.com/user-attachments/assets/a97c8fb2-4f97-4c2a-a90b-9d95dbde84fd" /> ## Required Minimum Privileges * Organization Manager role (Owner/Admin privileges are not required) * Works even with `access_all=false` * Only access rights to the target collection are required (`manage` privilege is not required) ## Attack Scenario A restricted Manager (intended for read/use-only access) directly invokes the API to update collection settings, elevate their own privileges to `manage=true`, and even delete the collection. This allows the user to bypass operational access restrictions and effectively gain administrator-equivalent control over the collection. ## Potential Impact * **Confidentiality:** Expansion of access scope through unauthorized privilege escalation and configuration changes. * **Integrity:** Unauthorized modification of collection settings and assignments; potential disabling of access controls. * **Availability:** Deletion of collections may disrupt business operations.