Critical
CVSS 9.1 Broken Authentication Responsible Disclosure
Disclosure
Unauthenticated OTP Send + Verify Chain (Phone Takeover)
OTP send and verify endpoints accept unlimited calls without rate limit enabling 6-digit OTP brute force phone takeover.
- Target
- West African B2B Fintech
- Category
- Broken Authentication
- Channel
- Responsible Disclosure
- Disclosed
- 2026-04
Redaction note
Vendor identity withheld.
This finding is documented here as part of MemCyber’s public disclosure record. The vendor has been anonymized to a sector and region descriptor. Full technical detail — including root cause, reproducible proof-of-concept, remediation guidance, and vendor attribution where granted — is available to qualified prospects under NDA.
Coordinated disclosure
How we handled it.
- Reported to the vendor via Responsible Disclosure with a reproducible proof-of-concept.
- Triage + remediation window coordinated with the vendor security team.
- Fix verified before any public reference.
- This record published only after the embargo period closed.