CVE-2021-21271 Detail

Current Description

Tendermint Core is an open source Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language - and securely replicates it on many machines. Tendermint Core v0.34.0 introduced a new way of handling evidence of misbehavior. As part of this, we added a new Timestamp field to Evidence structs. This timestamp would be calculated using the same algorithm that is used when a block is created and proposed. (This algorithm relies on the timestamp of the last commit from this specific block.) In Tendermint Core v0.34.0-v0.34.2, the consensus reactor is responsible for forming DuplicateVoteEvidence whenever double signs are observed. However, the current block is still “in flight” when it is being formed by the consensus reactor. It hasn’t been finalized through network consensus yet. This means that different nodes in the network may observe different “last commits” when assigning a timestamp to DuplicateVoteEvidence. In turn, different nodes could form DuplicateVoteEvidence objects at the same height but with different timestamps. One DuplicateVoteEvidence object (with one timestamp) will then eventually get finalized in the block, but this means that any DuplicateVoteEvidence with a different timestamp is considered invalid. Any node that formed invalid DuplicateVoteEvidence will continue to propose invalid evidence; its peers may see this, and choose to disconnect from this node. This bug means that double signs are DoS vectors in Tendermint Core v0.34.0-v0.34.2. Tendermint Core v0.34.3 is a security release which fixes this bug. As of v0.34.3, DuplicateVoteEvidence is no longer formed by the consensus reactor; rather, the consensus reactor passes the Votes themselves into the EvidencePool, which is now responsible for forming DuplicateVoteEvidence. The EvidencePool has timestamp info that should be consistent across the network, which means that DuplicateVoteEvidence formed in this reactor should have consistent timestamps. This release changes the API between the consensus and evidence reactors.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  GitHub, Inc.
Base Score:  6.5 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to nvd@nist.gov.

Hyperlink Resource
https://github.com/tendermint/tendermint/blob/v0.34.3/CHANGELOG.md#v0.34.3 Release Notes  Third Party Advisory 
https://github.com/tendermint/tendermint/commit/a2a6852ab99e4a0f9e79f0ea8c1726e262e25c76 Patch  Third Party Advisory 
https://github.com/tendermint/tendermint/security/advisories/GHSA-p658-8693-mhvg Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-400 Uncontrolled Resource Consumption Provider acceptance level GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-21271
NVD Published Date:
01/26/2021
NVD Last Modified:
02/08/2021
Source:
GitHub, Inc.