Use-After-Free in tremor-script (CVE-2021-39228)
Summary
Vulnerability in tremor-script (CVE-2021-39228). Successful exploitation can lead to full system takeover. Exploitable via patch. Mitigation: upgrade to 0.11.6 or later.
Original description
The description as published by the source.
Tremor is an event processing system for unstructured data. A vulnerability exists between versions 0.7.2 and 0.11.6. This vulnerability is a memory safety Issue when using patch or merge on state and assign the result back to state. In this case, affected versions of Tremor and the tremor-script crate maintains references to memory that might have been freed already. And these memory regions can be accessed by retrieving the state, e.g. send it over TCP or HTTP. This requires the Tremor server (or any other program using tremor-script) to execute a tremor-script script that uses the mentioned language construct. The issue has been patched in version 0.11.6 by removing the optimization and always cloning the target expression of a Merge or Patch. If an upgrade is not possible, a possible workaround is to avoid the optimization by introducing a temporary variable and not immediately reassigning to state.
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-2021-39228 has been found in tremor-script.
Attackers can target a specific entry point like patch over the network to misuse the product.
Successful exploitation can lead to full system takeover.
What to do: upgrade tremor-script to 0.11.6 or later.
If unsure, ask your IT team or search "tremor-script CVE-2021-39228" on the vendor's site.
CVE-2021-39228 (tremor-script) — CWE-416
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: patch / merge / state
Patched: 0.11.6 — 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.
Use-after-free (CWE-416) exists in tremor-script. Attackers reach the vulnerable code path via patch without authentication.
Check the vendor advisory for the affected versions of tremor-script. Attack surface: patch / merge / state.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 0.11.6.
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 'tremor-script' . 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
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1Identify exposure identify
grep -r 'tremor-script' . | 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
tremor-script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 tremor-script to 0.11.6ステージング環境で 0.11.6 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 github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com