Bitcoin Core Vulnerability Allows Remote Denial of Service

CVE-2024-35202

What is CVE-2024-35202?

CVE-2024-35202 is a vulnerability identified in Bitcoin Core, a widely used open-source software that facilitates the functioning of the Bitcoin network. This vulnerability affects versions prior to 25.0 and enables remote attackers to exploit specific flaws in handling block transactions, leading to a denial of service. Such an attack could have a detrimental impact on organizations utilizing Bitcoin Core, as it could disrupt operations by causing nodes to crash and potentially hindering network services.

Technical Details

The vulnerability arises due to improper message handling, particularly in the processing of block transactions. It allows an attacker to send a crafted blocktxn message with transactions that are not reflected in the block's merkle root. When this occurs, it may trigger assertion failures that lead to the unexpected termination of a node. The flaw exists in the way the FillBlock function can be called more than once for a single PartiallyDownloadedBlock instance, which aggravates the situation.

Impact of the Vulnerability

1. Denial of Service (DoS): The primary impact is the potential for attackers to cause nodes to crash, resulting in significant disruptions in Bitcoin network operations. This denial of service can hinder transaction processing and affect user accessibility to the network.

2. Network Reliability: Exploitation of this vulnerability could compromise the reliability of the Bitcoin network. Frequent node crashes would lead to instability, making it challenging for users and other applications to rely on the integrity and availability of the network.

3. Increased Maintenance Costs: Organizations relying on Bitcoin Core may face increased operational and maintenance costs, as they would need to implement additional monitoring and recovery protocols in response to potential attacks exploiting this vulnerability.

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