btcd: Interpretation Conflict
CVE-2024-34478 is a high-severity interpretation conflict vulnerability in btcd, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 0.24.0 as the first without the flaw, so updating btcd to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update btcd to 0.24.0 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CISA (ADP).
Official description
btcd before 0.24.0 does not correctly implement the consensus rules outlined in BIP 68 and BIP 112, making it susceptible to consensus failures. Specifically, it uses the transaction version as a signed integer when it is supposed to be treated as unsigned. There can be a chain split and loss of funds.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- delvingbitcoin.org/t/disclosure-btcd-consensus-bugs-due-to-usage-of-signed-transaction-version/455Issue Tracking
- github.com/btcsuite/btcd/blob/e4c88c3a3ecb1813529bf3dddc7a865bd418a6b8/blockchain/chain.go#L383C1-L392C3Product
- github.com/btcsuite/btcd/blob/e4c88c3a3ecb1813529bf3dddc7a865bd418a6b8/txscript/opcode.go#L1172C1-L1178C3Product
Recent Interpretation Conflict vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.3 High severity
- 7.5 High severity
- 7.5 High severity
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