WHAT IS A TEARDROP ATTACK?

Cyber threats attacking the cryptocurrency ecosystem are becoming more sophisticated as it matures. The teardrop attack, a type of denial-of-service (DoS) attack, is one of these concerning cyberattacks. Originally a network-level vulnerability, their adaptation to cryptocurrency systems highlights the ingenuity and versatility of malicious actors.

Imagine cutting a letter into pieces and placing each one in a different envelope. Someone puts the pieces back together at the destination to read the full letter. A teardrop attack is like sending envelopes with missing or overlapping parts, which makes it impossible to recreate the original letter. The receiver may become overwhelmed and shut down due to this confusion.

But what does it have to do with cryptocurrency?

Cryptocurrency systems rely heavily on network communication. Transactions, block propagation and other essential functions involve sending data across the internet in packets. These packets are reassembled by nodes that maintain the blockchain and process transactions.

A teardrop attack targeting specific nodes or network participants tries to interfere with regular operations to take advantage of weaknesses in wallets, exchanges or blockchain networks. For instance, by sending malformed packets, attackers can overwhelm the server’s reassembly process, causing it to crash or become unresponsive.

If a teardrop attack is effective, it may open the door for other attacks. For instance, attackers may attempt to take advantage of other weaknesses to obtain unauthorized access or alter data when the server is unavailable or having trouble reassembling packets. Therefore, understanding and addressing the consequences of such attacks is crucial because they have the potential to compromise the integrity of blockchain networks.

Attackers can interfere with consensus processes, transaction validation or node-to-node communication by focusing on particular nodes or servers. This can lead to network fragmentation, delayed processing or even a complete halt in operations. An attacker might, for instance, flood a crucial node in a permissionless blockchain — e.g., Bitcoin — or a validating node in a permissioned blockchain with erroneous data packets, rendering it inoperable. Because nodes depend on regular communication to reach consensus, these interruptions may lead to vulnerabilities that let attackers exploit network irregularities.

For example, if certain nodes are temporarily disconnected or non-functional, attackers could attempt to manipulate the data flow, triggering double-spending attacks or introducing erroneous transactions.

Additionally, teardrop attacks can target services connected to blockchain ecosystems, such as wallet providers and cryptocurrency exchanges, rather than the blockchain infrastructure itself. These services mainly depend on constant communication between users and servers for seamless transactions and service availability.

Teardrop attacks on exchanges can disrupt trading, withdrawals and other crucial services. In addition to negatively affecting specific users, this harms the exchange’s reputation and could result in losses for traders and investors. Furthermore, frequent attacks or prolonged outages may cause users to lose faith in the platform, harming its user base.