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Monthly Security Review: June 2024

July 1, 2024
4 min read

Security at a Glance 👀

DeFi Sector

  • UwU Lend Hacks

On June 10 and 13, UwU Lend suffered attacks resulting in losses exceeding $23M.

The root cause of the first attack was Vulnerable Price Dependency. The lending pool fetched prices from 11 sources, including 5 current (AMM) prices from Curve, 5 Curve oracle (EMA) prices, and one Uniswap (TWAP) price, ultimately taking the median. Since current prices could be manipulated within a single transaction, the attacker used a flash loan to drastically alter the 5 current prices, causing the fetched price to be the minimum or maximum of the oracle prices. This resulted in a loss of approximately $20M.

On June 13, the UwU Lend team restarted the protocol and got attacked again. The attacker added uSUSDe and WETH as collateral and then borrowed WETH based on the LTV. The uSUSDe did not participate in the LTV but did in the health factor calculation during liquidity withdrawal, allowing the attacker to withdraw more WETH and profit.

Notably, white hat makemake_kbo tweeted that he had reported the vulnerability a year ago and contacted the project team without a response, eventually issuing a warning on Twitter.

  • Velocore Hack

Root Cause: A lack of check on effectiveFee1e9 led to an underflow in the velocore__execute function.

After the attack, Linea halted block production for 1 hour. For L2 projects, having an emergency response mechanism is more effective than pausing the entire chain. 👉 Learn about the world's first crypto hack monitoring and blocking platform here.

  • Holograph Hack

Holograph announced that a former contractor exploited the protocol to mint additional HLG.

Many past attacks have shown that projects often compromise private key management for convenience. This exposes them to severe risks of internal and external attacks gaining admin permissions or private keys. Using Phalcon for external monitoring allows one-click operational monitoring, enabling early detection and loss minimization.

Other

  • DMM Exchange Hack

In early June, DMM Exchange disclosed a security incident where 4,502.9 BTC (over $300M) were stolen on May 31 (UTC).

Without more details from DMM, the cause remains unknown. However, the hacker's address and DMM's normal address shared the same first five and last two characters, and the stolen BTC was from a multisig address. Speculation suggests an off-chain attack replaced the transfer address, deceiving personnel into signing the transaction. Use MetaSleuth to track the funds here.

  • Kraken

On June 19, Kraken's Chief Security Officer, Nick Percoco, disclosed on X that they had received a report of an "extremely critical" vulnerability from a security company through their bug bounty program. The report claimed to have found a vulnerability that could artificially increase account balances. However, after Kraken fixed the vulnerability, they discovered some suspicious behavior during negotiations with the security company, involving $3 million. Nick Percoco's Post: View Post

CertiK later claimed responsibility for the matter on X, disclosed more information, and explained their actions. They emphasized that they had conducted multi-day tests on Kraken and had already returned the funds. This incident sparked intense discussion within the community.CertiK's Post: View Post Check out the root cause here and the sample transaction here.

  • CoinStats

CoinStats suffered a $2 million loss in an attack. Their CEO stated that the breach was due to a social engineering attack on an employee, which compromised their AWS infrastructure. Click here to learn more

Blog Articles

BlockSec has curated the "Solana Simplified" series, which includes articles on Solana's basic concepts, tutorials on writing Solana smart contracts and guides for analyzing Solana transactions. The goal is to help readers understand the Solana ecosystem and master essential skills for developing projects and conducting transactions on Solana.

01: Master Solana Core Concepts in One Read

02: Writing Your First Solana Smart Contract from Scratch

03: Understand Solana Transactions in 5 Minutes

BlockSec X Solana Summit

From June 20 to June 22, BlockSec proudly presented at the 2024 Solana Summit APAC in KL. Looking forward to meeting you all at more global events in the future!

Phalcon Explorer now fully supports Solana!

Phalcon Explorer introduces new features to enhance the user and developer experience, including:

🚀 Clarified account relationships & token changes

🚀 MEV transaction tagging & 300M+ address labels

🚀 Accurate, clear function call hierarchies with expandable levels

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~$18M Lost: jaredFromSubway, Aztec & More | BlockSec Weekly
Security Insights

~$18M Lost: jaredFromSubway, Aztec & More | BlockSec Weekly

This weekly blockchain security report covers June 15 to June 21, 2026, with 3 notable incidents across Ethereum and BNB Chain totaling approximately $18.3M in losses. Two incidents are analyzed in detail. Based on on-chain analysis, the highlighted jaredFromSubway incident reveals a reversed approval attack pattern: unlike traditional exploits where attackers abuse vulnerabilities in trusted DeFi contracts to drain user-approved assets, this MEV bot proactively approved its own assets to untrusted third-party contracts for arbitrage. The attacker constructed fake wrapper tokens and swap pools that emitted real events but never consumed the granted allowances, with reported total losses of ~$15M. The report also covers Aztec's second exploit in three days, where a missing equality constraint between two witnesses for `old_data_root` in the escape hatch ZK circuit allowed the attacker to prove ownership of fabricated notes against a fake Merkle tree while passing on-chain root validation.

~$5.98M Lost: Aztec, Raydium & More | BlockSec Weekly
Security Insights

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This weekly blockchain security report covers the period of June 8 to June 14, 2026, analyzing 4 notable incidents across Ethereum and Solana with total losses of approximately $5.98M. The highlighted events include Aztec Connect, where a missing input validation allowed the rollup's proof path and L1 settlement to reach inconsistent states, and Raydium, where a missing validation check on the legacy AMM v3 program allowed an attacker to manipulate the LP token redemption calculation and drain four pools. Both vulnerabilities had been live for years before exploitation. The report examines attack types including lack of input validation, integer overflow, and governance capture.

Zcash Orchard Soundness Bug Analysis | BlockSec Weekly
Security Insights

Zcash Orchard Soundness Bug Analysis | BlockSec Weekly

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