criticalAccess Control
4 min read2026-06-12
IDOR to full account takeover via predictable UUIDv1
AN
anon
security researcher · vault ocean
Time-based UUIDs leaked creation order; enumerating them exposed password-reset tokens for any user.
UUIDv1 encodes a timestamp and node id, so tokens issued close together are highly predictable. By harvesting a few reset tokens and interpolating, an attacker could mint a valid token for any account. Fix: use UUIDv4 (CSPRNG) for anything security-sensitive, and bind reset tokens to the user + a server-side secret.
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AN
Written by
anon
Security researcher · Vault Ocean contributor