CVE-2021-43839

Drainage of FeeCollector's Block Transaction Fees

HIGH
7.5
CVSS Score
Published: December 21, 2021 at 04:50 PM UTC
Updated: June 17, 2026 at 04:11 AM UTC
4 products affected across 2 vendorsCronosEvmosEthermint

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Severity
HIGH7.5
Exploit prediction
EPSS 1%

Description

Cronos is a commercial implementation of a blockchain. In Cronos nodes running versions before v0.6.5, it is possible to take transaction fees from Cosmos SDK's FeeCollector for the current block by sending a custom crafted MsgEthereumTx. This problem has been patched in Cronos v0.6.5. There are no tested workarounds. All validator node operators are recommended to upgrade to Cronos v0.6.5 at their earliest possible convenience.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.6.5
Affected range stops below 0.6.5, so it looks safe — our inference, not a vendor statement
v < 0.7.30.8.0 ≤ v ≤ 0.9.0
Affected range stops below 0.7.3, so it looks safe — our inference, not a vendor statement
v ≤ 0.4.2
v < 0.6.5
Affected range stops below 0.6.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-670

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