{"id":"CVE-2021-43839","aliases":["GHSA-f854-hpxv-cw9r"],"title":"Drainage of FeeCollector's Block Transaction Fees in cronos","summary":"Drainage of FeeCollector's Block Transaction Fees in cronos","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","vendor":"crypto-org-chain","product":"github.com/crypto-org-chain/cronos","ecosystem":"go","affected":["github.com/crypto-org-chain/cronos < 0.6.5","github.com/tharsis/ethermint >= 0.8.0, < 0.10.0","github.com/tharsis/evmos <= 0.4.2","github.com/tharsis/ethermint < 0.7.3"],"patched":["github.com/crypto-org-chain/cronos 0.6.5","github.com/tharsis/ethermint 0.10.0","github.com/tharsis/ethermint 0.7.3"],"published":"2022-01-06","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-f854-hpxv-cw9r","references":[{"url":"https://github.com/crypto-org-chain/cronos/security/advisories/GHSA-f854-hpxv-cw9r"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-43839"},{"url":"https://github.com/crypto-org-chain/cronos/pull/270"},{"url":"https://github.com/crypto-org-chain/cronos/commit/150ef237b37ac28c8136e1c0f494932860b9ebe8"},{"url":"https://github.com/crypto-org-chain/cronos"}],"tags":["osv","go"],"epss":0.01313,"epssPercentile":0.69439,"ingestedAt":"2026-07-09T18:56:36.337Z","slug":"CVE-2021-43839","body":"## Overview\n\n### Impact\nIn 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.\n\nUser funds and balances are safe.\n\n\n### Patches\nThis problem has been patched in Cronos v0.6.5 on the mempool level.\nThe next network upgrade with consensus-breaking changes will patch it on the consensus level.\n\n### Workarounds\nThere are no tested workarounds. All validator node operators are recommended to upgrade to Cronos v0.6.5 at their earliest possible convenience.\n\n### Credits\nThank you to @zb3 for reporting this issue on [Cronos Immunefi Bug Bounty Program](https://immunefi.com/bounty/cronos/), to @cyril-crypto for reproducing the issue and to @yihuang and @thomas-nguy for patching the issue on the CheckTx (mempool) and the DeliverTx (consensus) levels.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open a discussion in [crypto-org-chain/cronos](https://github.com/crypto-org-chain/cronos/discussions/new)\n* Email us at [chain@crypto.org](mailto:chain@crypto.org)\n\n\n## Affected packages\n\n- `github.com/crypto-org-chain/cronos < 0.6.5`\n- `github.com/tharsis/ethermint >= 0.8.0, < 0.10.0`\n- `github.com/tharsis/evmos <= 0.4.2`\n- `github.com/tharsis/ethermint < 0.7.3`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/crypto-org-chain/cronos 0.6.5`\n- `github.com/tharsis/ethermint 0.10.0`\n- `github.com/tharsis/ethermint 0.7.3`","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}