Haven Protocol Hack

USD impact unconfirmed Not disclosed
Haven
Asset validation and unauthorized minting

What happened

Starting June 22, 2021, attackers exploited several Haven Protocol validation flaws to create assets illegitimately and conceal conversion amounts. Some resulting inflation could not be quantified. On July 20, Haven rolled the chain back to block 886575 as part of its recovery plan.

Technical root cause

Asset-type, miner-reward and conversion checks failed to reject inconsistent transaction data. The combined incidents cannot be accurately summarized as a single confirmed USD loss.

How it happened

  1. Invalid miner-reward transactions passed asset checks, creating xBTC and xUSD.
  2. Malformed xJPY-to-xBTC transactions bypassed conversion validation.
  3. A separate bug hid mint and burn amounts, undermining supply accounting; the report says that bug did not itself create inflation.
  4. Zero-valued oracle records enabled further minting with an undetermined output value.
  5. The community approved a rollback to June 27 state. Conversion functionality remained paused while stronger validation was prepared.

Protocol details

Classification Protocol Validation
Protocol Type Exploit/Other
Protocol links Website @HavenXHV

Evidence

Build your security review skills

Work through hands-on labs covering real exploit mechanics, review techniques, and defensive patterns.

Start Free Trial Explore attack classes