CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
40.8%
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 βin flightβ when it is being formed by the consensus
reactor. It hasnβt been finalized through network consensus yet. This means that different nodes in the network may observe different βlast commitsβ 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 Vote
s 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.
This is a denial-of-service vector which impacts networks running Tendermint Core v0.34.0 - v0.34.2.
This problem has been patched in Tendermint Core v0.34.3. Networks running impacted versions of Tendermint Core should update immediately.
There are no workarounds, other than upgrading to a patched version of Tendermint Core.
If you have any questions or comments about this advisory:
github.com/tendermint/tendermint
github.com/tendermint/tendermint/blob/v0.34.3/CHANGELOG.md#v0.34.3
github.com/tendermint/tendermint/commit/a2a6852ab99e4a0f9e79f0ea8c1726e262e25c76
github.com/tendermint/tendermint/pull/5219
github.com/tendermint/tendermint/security/advisories/GHSA-p658-8693-mhvg
nvd.nist.gov/vuln/detail/CVE-2021-21271
pkg.go.dev/vuln/GO-2022-1052
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
40.8%