vulnerability / NVI-00014075 / Revision 1
@sync-in/server vulnerable to TOTP Brute-Force via `POST /api/app/sync/register`
GitHub lists this reviewed advisory for @sync-in/server. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.8 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
@sync-in/server
source listed<= 2.3.0
**Affected component:** Sync-in Server v2.3.0, `POST /api/app/sync/register`. **Required attacker capability:** Valid login and password for a TOTP-enabled account with desktop sync permission. ## Summary `POST /api/app/sync/register` accepts credentials and a TOTP code to register a desktop sync client. In the vulnerable version, on a failed TOTP attempt, `SyncClientsManager.register()` called `updateAccesses(user, ip, false)`, which hit a freeze branch that wrote `passwordAttempts` back unchanged. The counter never reached `USER_MAX_PASSWORD_ATTEMPTS` (10), so the account lockout gate never fired for repeated TOTP failures through this endpoint. A successful TOTP guess registers a sync client and returns a `{clientId, clientToken}` pair, provided the account has the required desktop app permission and the registration payload is valid. The token can then be exchanged via `POST /api/app/sync/auth/cookie` for an authenticated session. While the guessed TOTP code is still valid, and because the attacker already knows the password, the attacker can also call `POST /api/auth/2fa/disable` to remove MFA. ## Details The endpoint is declared at `sync.controller.ts` line 71. `@AuthTo
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-274f-6w77-8qm9 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.