CometbftApplication

CVE-2023-34451

HIGH · 8.2 CVSS v3.1 Published 2023-07-03
Fix available
A fix is available. Upgrade to 0.34.29 / 0.37.2 or later.
See remediation →
91/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
CometBFT is a Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine and replicates it on many machines. The mempool maintains two data structures to keep track of outstanding transactions: a list and a map. These two data structures are supposed to be in sync all the time in the sense that the map tracks the index (if any) of the transaction in the list. In `v0.37.0`, and `v0.37.1`, as well as in `v0.34.28`, and all previous releases of the CometBFT repo2, it is possible to have them out of sync. When this happens, the list may contain several copies of the same transaction. Because the map tracks a single index, it is then no longer possible to remove all the copies of the transaction from the list. This happens even if the duplicated transaction is later committed in a block. The only way to remove the transaction is by restarting the node. The above problem can be repeated on and on until a sizable number of transactions are stuck in the mempool, in order to try to bring down the target node. The problem is fixed in releases `v0.34.29` and `v0.37.2`. Some workarounds are available. Increasing the value of `cache_size` in `config.toml` makes it very difficult to effectively attack a full node. Not exposing the transaction submission RPC's would mitigate the probability of a successful attack, as the attacker would then have to create a modified (byzantine) full node to be able to perform the attack via p2p.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-401

Allocated memory is never released on some path, so a long-running service or a repeatedly triggered request steadily consumes memory until performance degrades or the process crashes. Attackers exploit it by simply driving the leaking path. Remediation is pairing every allocation with a release and using ownership patterns or tooling to catch what leaks.

General guidance for the memory leak class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CometbftApplication
Affected:>= 0.34.28, < 0.34.29>= 0.37.0, < 0.37.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.34.29 / 0.37.2 or later
Fixed in 0.34.290.37.2
Vendor patch github.com →
Recommended fix High confidence

v0.34.29 for 0.34.x line or v0.37.2 for 0.37.x line

  1. Determine your current CometBFT version by checking the version file or running `cometbft version`
  2. If running v0.34.x (>=0.34.28), upgrade to v0.34.29
  3. If running v0.37.x (>=0.37.0), upgrade to v0.37.2
  4. After upgrading, restart the node to ensure clean mempool state
  5. Alternatively, as a configuration mitigation, edit config.toml and increase the `cache_size` parameter to make exploitation more difficult

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-34451 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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