{"answers":{"affected":"3 open source packages ship an affected version, including github.com/filecoin-project/lotus. It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-21405 in the wild and no public exploit code.","fix":"Upgrade github.com/filecoin-project/lotus to 1.5.0 or later.","what":"CVE-2021-21405 is a medium-severity vulnerability in filecoin-project lotus, published on 15 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-21405 and fix it if it is affected.\n\nWhat it is: CVE-2021-21405 is a medium-severity vulnerability in filecoin-project lotus, published on 15 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-21405 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/filecoin-project/lotus (Go): affected all versions; fixed in 1.5.0\n- github.com/filecoin-project/lotus (Go): affected all versions; fixed in 1.5.0\n- github.com/filecoin-project/lotus (Go): affected all versions; fixed in 1.5.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-21405/ (Markdown: https://insights.sbomify.com/CVE-2021-21405/index.md)","id":"CVE-2021-21405","markdown":"https://insights.sbomify.com/CVE-2021-21405/index.md","name":"CVE-2021-21405","record":{"aliases":["GHSA-4g52-pqcj-phvh","GO-2022-0905"],"analysis":{"component_type":"server_software","fix_type":"patch","impacts":["denial_of_service","other"],"network_reachable":"yes","non_default_config":false,"product_category":"Filecoin node implementation","requires_auth":"none","summary":"BLS signature malleability allows creating duplicate block CIDs, potentially causing valid blocks to be rejected and punishing miners.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"lotus","vendor":"filecoin"}],"cvss":{"score":5.9,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature"}],"description":"Lotus is an Implementation of the Filecoin protocol written in Go. BLS signature validation in lotus uses blst library method VerifyCompressed. This method accepts signatures in 2 forms: \"serialized\", and \"compressed\", meaning that BLS signatures can be provided as either of 2 unique byte arrays. Lotus block validation functions perform a uniqueness check on provided blocks. Two blocks are considered distinct if the CIDs of their blockheader do not match. The CID method for blockheader includes the BlockSig of the block. The result of these issues is that it would be possible to punish miners for valid blocks, as there are two different valid block CIDs available for each block, even though this must be unique. By switching from the go based `blst` bindings over to the bindings in `filecoin-ffi`, the code paths now ensure that all signatures are compressed by size and the way they are deserialized. This happened in https://github.com/filecoin-project/lotus/pull/5393.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"BLS Signature \"Malleability\"","id":"CVE-2021-21405","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":null,"products":[],"type":"other","year":"2021"},"n_packages":3,"n_references":3,"next":{"headline":"Command Injection vulnerability in the Setup Wizard","id":"CVE-2021-21406"},"packages":[{"ecosystem":"Go","fixed":["1.5.0"],"introduced":["0"],"last_affected":[],"package":"github.com/filecoin-project/lotus","purl":null,"source":"GHSA-4g52-pqcj-phvh"},{"ecosystem":"Go","fixed":["1.5.0"],"introduced":["0"],"last_affected":[],"package":"github.com/filecoin-project/lotus","purl":"pkg:golang/github.com/filecoin-project/lotus","source":"GHSA-4g52-pqcj-phvh"},{"ecosystem":"Go","fixed":["1.5.0"],"introduced":["0"],"last_affected":[],"package":"github.com/filecoin-project/lotus","purl":"pkg:golang/github.com/filecoin-project/lotus","source":"GO-2022-0905"}],"prev":{"headline":"Crash due to malformed relay protocol message","id":"CVE-2021-21404"},"products":["lotus"],"published":"2021-04-15","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-03","vendors":["filecoin-project"]},"summary":"BLS signature malleability allows creating duplicate block CIDs, potentially causing valid blocks to be rejected and punishing miners.","url":"https://insights.sbomify.com/CVE-2021-21405/"}