Hacker turns 25 cents into 46 billion fake Bitcoins to steal $770,000 — Symbiosis DeFi exchange bit by lack of basic bounds checking in smart contract
- ID
- 25884
- Status
- summarized
- Published
- 18 Sep 2026, 6:30 PM
- Fetched
- 18 Sep 2026, 6:59 PM
- Provider
- Tom's Hardware
- Category
- technology
- Original URL
- https://www.tomshardware.com/tech-industry/cryptocurrency/hacker-turns-25-cents-into-46-billion-fake-bitcoins-to-steal-usd770-000-symbiosis-defi-exchange-bit-by-lack-of-basic-bounds-checking-in-smart-contract
- Source URL
- https://www.tomshardware.com/feeds/all
Summary
- Score
- 4.0
- Created
- 18 Sep 2026, 6:59 PM
- Tags
- Audience
- developerssaas_founders
What happened
A hacker exploited a missing bounds check in a Symbiosis DeFi exchange smart contract, minting 46 billion fake Bitcoins from a 25-cent deposit and stealing $770,000. The vulnerability was a basic input validation failure rather than a novel cryptographic attack.
Why it matters
If you ship or audit smart contracts, this is a concrete reminder that missing bounds checks on token amounts can be catastrophic — review any contract that accepts user-supplied quantities and ensure upper limits are enforced before minting or transferring.
Discussion angle
How a trivial input validation bug (no upper-bound check on token minting) caused a $770K loss — and whether traditional web app security practices like bounds checking are under-applied in smart contract development.