CVE-2024-38365

Published Oct 11, 2024

Last updated a month ago

Overview

Description
btcd is an alternative full node bitcoin implementation written in Go (golang). The btcd Bitcoin client (versions 0.10 to 0.24) did not correctly re-implement Bitcoin Core's "FindAndDelete()" functionality. This logic is consensus-critical: the difference in behavior with the other Bitcoin clients can lead to btcd clients accepting an invalid Bitcoin block (or rejecting a valid one). This consensus failure can be leveraged to cause a chain split (accepting an invalid Bitcoin block) or be exploited to DoS the btcd nodes (rejecting a valid Bitcoin block). An attacker can create a standard transaction where FindAndDelete doesn't return a match but removeOpCodeByData does making btcd get a different sighash, leading to a chain split. Importantly, this vulnerability can be exploited remotely by any Bitcoin user and does not require any hash power. This is because the difference in behavior can be triggered by a "standard" Bitcoin transaction, that is a transaction which gets relayed through the P2P network before it gets included in a Bitcoin block. `removeOpcodeByData(script []byte, dataToRemove []byte)` removes any data pushes from `script` that contain `dataToRemove`. However, `FindAndDelete` only removes exact matches. So for example, with `script = "<data> <data||foo>"` and `dataToRemove = "data"` btcd will remove both data pushes but Bitcoin Core's `FindAndDelete` only removes the first `<data>` push. This has been patched in btcd version v0.24.2. Users are advised to upgrade. There are no known workarounds for this issue.
Source
security-advisories@github.com
NVD status
Awaiting Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.4
Impact score
5.2
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Severity
HIGH

Weaknesses

security-advisories@github.com
CWE-670

Social media

Hype score
Not currently trending