CVE Vulnerability

CVE-2021-31876

Bitcoin Core 0.12.0 through 0.21.1 does not properly implement the replacement policy specified in BIP125, which makes it easier for attackers to trigger a loss of funds, or a denial of service attack against downstream projects such as Lightning network nodes. An unconfirmed child transaction with nSequence = 0xff_ff_ff_ff, spending an unconfirmed parent with nSequence <= 0xff_ff_ff_fd, should be replaceable because there is inherited signaling by the child transaction. However, the actual PreChecks implementation does not enforce this. Instead, mempool rejects the replacement attempt of the unconfirmed child transaction.

6.4 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 4.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

6.5 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References
Link Resource
https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures#CVE-2021-31876 Third Party Advisory
https://bitcoinops.org/en/newsletters/2021/05/12/ Vendor Advisory
https://bitcoinops.org/en/topics/replace-by-fee/ Vendor Advisory
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2021-May/018893.html Mailing List Third Party Advisory
https://github.com/bitcoin/bitcoin Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:bitcoin:bitcoin:*:*:*:*:*:*:*:*
Information

Published : 2021-05-13 10:15

Updated : 2021-05-26 08:12

NVD link : CVE-2021-31876

Mitre link : CVE-2021-31876

Products Affected
No products.
CWE
CWE-863