CVE-2024-38365: 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-i...

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.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

EPSS Probability

1.02%

59.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-670

Affected Software

Vendor	Product	Versions
Btcd Project	Btcd	>= 0.10.0, < 0.24.2

References

Timeline

Published: Oct 11, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-38365?

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.

How severe is CVE-2024-38365?

CVE-2024-38365 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2024-38365?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.