Categories
CVE-2021-23387

Open Redirect in trailing-slash (CVE-2021-23387)

Summary

Vulnerability in trailing-slash (CVE-2021-23387). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.0.1 or later.

Original description

The description as published by the source.

The package trailing-slash before 2.0.1 are vulnerable to Open Redirect via the use of trailing double slashes in the URL when accessing the vulnerable endpoint (such as https://example.com//attacker.example/). The vulnerable code is in index.js::createTrailing(), as the web server uses relative URLs instead of absolute URLs.

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-2021-23387 has been found in trailing-slash.
Risk of unauthorized operations or information disclosure.
What to do: upgrade trailing-slash to 2.0.1 or later.
If unsure, ask your IT team or search "trailing-slash CVE-2021-23387" on the vendor's site.

CVE-2021-23387 (trailing-slash) — CWE-601
Attack vector: remote (network-reachable) / unauthenticated
Patched: 2.0.1 — 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.

❓ What is the problem

A vulnerability (CWE-601) exists in trailing-slash.

📍 Affected scope

Check the vendor advisory for the affected versions of trailing-slash.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 2.0.1.

🛡️ 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. Run grep -r 'trailing-slash' . 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

  1. 1
    Identify exposure identify
    grep -r 'trailing-slash' . | 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 trailing-slash を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply patch patch
    Upgrade trailing-slash to 2.0.1

    ステージング環境で 2.0.1 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。

  3. 3
    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

npm trailing-slash
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.0.1"}]}]

References

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