Vulnerability in github.com/filecoin-project/lotus (CVE-2021-21405)
Summary
Vulnerability in github.com/filecoin-project/lotus (CVE-2021-21405). Data can be tampered with by attackers. Exploitable via blst. Mitigation: upgrade to 1.5.0 or later.
Original description
The description as published by the source.
Impact
- 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.
Patches
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
References
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-21405 has been found in github.com/filecoin-project/lotus.
Attackers can target a specific entry point like blst over the network to misuse the product.
Data can be tampered with by attackers.
What to do: upgrade github.com/filecoin-project/lotus to 1.5.0 or later.
If unsure, ask your IT team or search "github.com/filecoin-project/lotus CVE-2021-21405" on the vendor's site.
CVE-2021-21405 (github.com/filecoin-project/lotus) — CWE-347
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: blst
Patched: 1.5.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-347) exists in github.com/filecoin-project/lotus. Attackers reach the vulnerable code path via blst without authentication.
Check the vendor advisory for the affected versions of github.com/filecoin-project/lotus. Attack surface: blst.
Severity: ?. Data can be tampered with by attackers.
Update to 1.5.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/filecoin-project/lotus' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/filecoin-project/lotus' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/filecoin-project/lotusを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/filecoin-project/lotus to 1.5.0ステージング環境で 1.5.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- web github.com
- web github.com
- web gist.github.com