Safe Dollar Hack

TOTAL LOST $248K
Low Incentive Rewards Exploit / Other polygon

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain polygon Incident surface
Recovered - No recovery reported
All-Time Rank #1221 By amount stolen
Protocol Type Exploit/Other Target category

Incident Overview

The attacker's address:

https://polygonscan.com/address/0xfedc2487…be7ebd

The attack transaction:

https://polygonscan.com/tx/0x1360315a…ee5c14

The attack took the use of a flaw in Safe Dollar reward structure to alter the accSdoPerShare value, allowing it to claim a big number of SDO for each token deposited token.

In preparation, an initial deposit was placed into one of the protocol's Safe Farms:

https://polygonscan.com/tx/0x55dad44a…3a074b

Transfer fees are charged by PLX, the currency that SafeDollar was incentivizing. These fees are meant to be borne by the user, however, they were taken from the rewarder balance instead during withdrawal transactions.

The hacker used a deposit/withdraw loop to progressively drain the pool's PLX balance over the course of 101 transactions, resulting in a hugely inflated accSdoPerShare of 1,142,913,215,739,484,400 SDO being awarded for each PLX contributed.

Claiming rewards on the initial deposit produced a total of 831,309,277,244,108,000 SDO which were sold by the attacker.

Incident Report

Protocol / Project Safe Dollar
Date of Incident
Affected Chain(s) polygon
Attack Technique Incentive Rewards Exploit / Other
Classification Protocol Logic / Stablecoin
Primary Source View Post-Mortem

Protocol Information

Protocol Type Exploit/Other
Affected Token SDO
Smart Contract Language Solidity
Official Website www.safedollar.fi/
Protocol Twitter/X @safedollarfi

Market Context at Time of Hack

Token Categories
Store Of Value Stablecoin Asset-Backed Stablecoin USD Stablecoin Fiat Stablecoin Binance Ecosystem Binance Listing
Protocol Links
GitHub

What the Attacker Needed to Succeed

Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.

Technical Knowledge Deep understanding of incentive rewards exploit / other and Solidity and EVM internals
Capital Required Seed capital to cover gas and initial position setup
On-Chain Access Ability to interact with polygon smart contracts and deploy a custom exploit contract
Protocol Analysis Identification of the exploitable vulnerability in Safe Dollar's contract logic - root cause: protocol logic / stablecoin
Execution Speed Precise transaction ordering and timing to exploit the vulnerability within a single atomic block
Obfuscation Plan A strategy to launder and move stolen funds - typically through mixers, cross-chain bridges, or decentralized DEX swaps to resist tracing

What Auditors Should Check

Could this have been caught in audit? Likely — with a thorough Incentive Rewards Exploit / Other audit checklist and test coverage

If you're auditing a protocol with similar architecture to Safe Dollar, these are the critical security checks that could have prevented this incident (June 2021).

  • Verify all logic paths related to Incentive Rewards Exploit / Other are guarded by proper access controls and input validation
  • Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs

Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.

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Sources & References

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