CVE-2019-25220Network attack vector

Remote node crash via low-work header storage

Published Nov 18, 2024 · Updated Nov 18, 2024

Memory exhaustion in Bitcoin Core before 24.0.1 allows remote attackers to crash nodes by flooding them with low-difficulty header chains. The headers-first synchronization path commits presented headers to the in-memory block index before establishing that their chain has sufficient proof of work. A reusable crafted chain can exhaust a reachable peer's memory without authentication, terminating the node but not altering blockchain data.

CVSS severity7.5
High
EPSS probability0.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in Bitcoin Core before 24.0.1 allows remote attackers to crash nodes by flooding them with low-difficulty header chains. The headers-first synchronization path commits presented headers to the in-memory block index before establishing that their chain has sufficient proof of work. A reusable crafted chain can exhaust a reachable peer's memory without authentication, terminating the node but not altering blockchain data.

The record

CVE
CVE-2019-25220
Published
Nov 18, 2024
Updated
Nov 18, 2024
Vendor
Bitcoin Core
Product
Bitcoin Core
Classifications
T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 18, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 18, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <24.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bitcoin Core · Bitcoin Coreversion=0 <24.0.1

Published CVSS scores

7.5OSVCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.002Service Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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