Alchemix Transmuter

Summary

The StrategyMainnet contract grants unlimited token approvals to both the transmuter and router without implementing any approval management or revocation mechanisms, creating significant risk if either contract becomes compromised.

Vulnerability Details

Found two instances of unlimited approvals:

1. Transmuter Approval in Constructor:

2. Router Approval in Init:

Key Issues:

1. No way to revoke approvals

2. No way to remove router in emergency

3. No approval reset mechanism

4. Permanent unlimited access granted

Impact

If either transmuter or router is compromised:

• Attacker would have unlimited access to strategy's tokens

• No emergency mechanism to revoke access

• Must deploy new strategy to fix (expensive and time-consuming)

• All funds at risk until migration complete

Tools Used

• Manual review

Recommendations

Add approval remove function in emergency conditions