Summary
btcd did not correctly re-implement Bitcoin Core's "FindAndDelete()" functionality
FindAndDelete vs. removeOpcodeByData
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.
References
FindAndDelete: https://github.com/btcsuite/btcd/security/advisories/GHSA-27vh-h6mc-q6g8
Impact
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.
CVE-2024-38365 has a CVSS score of 7.4 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.24.2-beta.rc1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This has been patched in btcd version v0.24.2-beta.
Frequently Asked Questions
- What is CVE-2024-38365? CVE-2024-38365 is a high-severity security vulnerability in github.com/btcsuite/btcd (go), affecting versions < 0.24.2-beta.rc1. It is fixed in 0.24.2-beta.rc1.
- How severe is CVE-2024-38365? CVE-2024-38365 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/btcsuite/btcd are affected by CVE-2024-38365? github.com/btcsuite/btcd (go) versions < 0.24.2-beta.rc1 is affected.
- Is there a fix for CVE-2024-38365? Yes. CVE-2024-38365 is fixed in 0.24.2-beta.rc1. Upgrade to this version or later.
- Is CVE-2024-38365 exploitable, and should I be worried? Whether CVE-2024-38365 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2024-38365 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2024-38365? Upgrade
github.com/btcsuite/btcdto 0.24.2-beta.rc1 or later.