Categories
CVE-2021-21289

Mechanize is an open-source ruby library that makes automated web interaction easy. In Mechanize from version 2.0.0 and…

Summary

Vulnerability reported (CVE-2021-21289). Successful exploitation can lead to full system takeover.

Original description

The description as published by the source.

This security advisory has been created for public disclosure of a Command Injection vulnerability that was responsibly reported by @kyoshidajp (Katsuhiko YOSHIDA).

Impact

Mechanize >= v2.0, < v2.7.7 allows for OS commands to be injected using several classes' methods which implicitly use Ruby's Kernel.open method. Exploitation is possible only if untrusted input is used as a local filename and passed to any of these calls:

  • Mechanize::CookieJar#load: since v2.0 (see 208e3ed)
  • Mechanize::CookieJar#save_as: since v2.0 (see 5b776a4)
  • Mechanize#download: since v2.2 (see dc91667)
  • Mechanize::Download#save and #save! since v2.1 (see 98b2f51, bd62ff0)
  • Mechanize::File#save and #save_as: since v2.1 (see 2bf7519)
  • Mechanize::FileResponse#read_body: since v2.0 (see 01039f5)

Patches

These vulnerabilities are patched in Mechanize v2.7.7.

Workarounds

No workarounds are available. We recommend upgrading to v2.7.7 or later.

References

See https://docs.rubocop.org/rubocop/cops_security.html#securityopen for background on why Kernel.open should not be used with untrusted input.

For more information

If you have any questions or comments about this advisory, please open an issue in sparklemotion/mechanize.

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-2021-21289 has been found.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2021-21289" on the vendor's site.

CVE-2021-21289
Attack vector: remote (network-reachable) / unauthenticated
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.

❓ What is the problem

A vulnerability (unclassified) has been reported.

📍 Affected scope

Check the vendor advisory for the affected versions.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。

  2. 2
    Post-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

RubyGems mechanize
[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.7.7"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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