{"id":"GHSA-43fj-qp3h-hrh5","revision":"2dc04107ccc44707875f4f7cc81a007e","records":[{"revision":"2dc04107ccc44707875f4f7cc81a007e","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-43fj-qp3h-hrh5","aliases":["CVE-2026-41161"],"title":"Sync-in Server has Username Enumeration via Timing Attack","description":"### Summary\nThe `/api/auth/login` endpoint contains a logic flaw that allows unauthenticated remote attackers to enumerate valid usernames by measuring the application's response time.\n\n### Details\nThe logic flaw can be located at the below point in source:\nhttps://github.com/Sync-in/server/blob/7868bb2b3025f92e6c38087456304758713971b2/backend/src/applications/users/services/users-queries.service.ts#L91-L95\n\nEndpoints 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.\n\n### Validation\nTickTock 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.\n<img width=\"1302\" height=\"284\" alt=\"image\" src=\"https://github.com/user-attachments/assets/31eeb72a-c3c2-4057-ac69-c0c92f0bbd4e\" />\n\n### Impact\nAn 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.","state":0,"publishedAt":"2026-04-15T18:57:50+00:00","modifiedAt":"2026-05-12T17:16:56.9455+00:00","affected":[{"ecosystem":"npm","name":"@sync-in/server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"2.2.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"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","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/Sync-in/server/security/advisories/GHSA-43fj-qp3h-hrh5","https://nvd.nist.gov/vuln/detail/CVE-2026-41161","https://github.com/Sync-in/server","https://github.com/Sync-in/server/releases/tag/v2.2.0"],"sourceUrl":"https://github.com/advisories/GHSA-43fj-qp3h-hrh5","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-43fj-qp3h-hrh5","identifiers":["GHSA-43fj-qp3h-hrh5","CVE-2026-41161"]},"retained":false,"historicalAffected":[]}],"coverage":[]}