CVE-2024-38365 btcd did not correctly re-implement Bitcoin Core's "FindAndDelete()" functionality

What is CVE-2024-38365?

CVE-2024-38365 is a high-severity vulnerability in btcsuite btcd, published on 11 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-670

Which versions are affected by CVE-2024-38365?

3 open source packages ship an affected version, including github.com/btcsuite/btcd. It affects 1 product.

Products include Btcd Project Btcd.

How do I fix CVE-2024-38365?

Upgrade github.com/btcsuite/btcd to 0.24.2-beta.rc1 or later.

Is CVE-2024-38365 being exploited?

There is no known exploitation of CVE-2024-38365 in the wild and no public exploit code.

Other vulnerabilities in btcsuite btcd

• CVE-2022-44797 btcd mishandles witness size checking Critical 9.8
• CVE-2022-39389 Witness Block Parsing DoS Vulnerability in lnd High 8.2
• CVE-2024-34478 btcd susceptible to consensus failures High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as CVE-2024-36051, GHSA-27vh-h6mc-q6g8, GO-2024-3189.