GHSA-43fj-qp3h-hrh5
Suggest an improvement- Source
- https://github.com/advisories/GHSA-43fj-qp3h-hrh5
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-43fj-qp3h-hrh5/GHSA-43fj-qp3h-hrh5.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-43fj-qp3h-hrh5
- Aliases
-
- CVE-2026-41161
- Published
- 2026-04-15T18:57:50Z
- Modified
- 2026-05-12T17:16:56.945500Z
- Severity
-
- 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Sync-in Server has Username Enumeration via Timing Attack
- Details
-
Summary
The
/api/auth/loginendpoint contains a logic flaw that allows unauthenticated remote attackers to enumerate valid usernames by measuring the application's response time.Details
The logic flaw can be located at the below point in source: https://github.com/Sync-in/server/blob/7868bb2b3025f92e6c38087456304758713971b2/backend/src/applications/users/services/users-queries.service.ts#L91-L95
Endpoints used for authentication should respond to the user with a consistent cadence, preventing remote actors from deriving sensitive information about an application based on backend behavior. In the case of authentication endpoints, this timing discrepancy is often caused by short-circuiting due to the lack of a matched user to compare against - as is the case with Sync-in.
Validation
TickTock Enum (Burp Suite Extension) was utilized to validate this finding. Authentication attempts with a valid username see a response from the application at around 350-400ms on average, while invalid usernames are returned at only 95-100ms on average. <img width="1302" height="284" alt="image" src="https://github.com/user-attachments/assets/31eeb72a-c3c2-4057-ac69-c0c92f0bbd4e" />
Impact
An unauthenticated remote attacker can enumerate valid usernames. This significantly weakens the application's security posture by facilitating targeted brute-force attacks, stuffing, social engineering, and a suite of other more targeted attacks.
- Database specific
{ "github_reviewed_at": "2026-04-15T18:57:50Z", "nvd_published_at": "2026-05-08T14:16:33Z", "cwe_ids": [ "CWE-208" ], "severity": "MODERATE", "github_reviewed": true }- References
Affected packages
npm / @sync-in/server
Package
- Name
- @sync-in/server
- View open source insights on deps.dev
- Purl
- pkg:npm/%40sync-in/server