CVE-2021-41084

Vulnerability in org.http4s:http4s-client_2.12 (CVE-2021-41084)

Summary

Vulnerability in org.http4s:http4s-client_2.12 (CVE-2021-41084). Risk of unauthorized operations or information disclosure. Exploitable via Header.name. Mitigation: upgrade to 0.23.4 or later.

Original description

The description as published by the source.

http4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when untrusted user input is used to create any of the following fields: Header names (Header.nameå), Header values (Header.value), Status reason phrases (Status.reason), URI paths (Uri.Path), URI authority registered names (URI.RegName) (through 0.21). This issue has been resolved in versions 0.21.30, 0.22.5, 0.23.4, and 1.0.0-M27 perform the following. As a matter of practice http4s services and client applications should sanitize any user input in the aforementioned fields before returning a request or response to the backend. The carriage return, newline, and null characters are the most threatening.

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-2021-41084 has been found in org.http4s:http4s-client_2.12.
Attackers can target a specific entry point like Header.name over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade org.http4s:http4s-client_2.12 to 0.23.4 or later.
If unsure, ask your IT team or search "org.http4s:http4s-client_2.12 CVE-2021-41084" on the vendor's site.

CVE-2021-41084 (org.http4s:http4s-client_2.12) — CWE-74
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: Header.name / Header.value / Status.reason / Uri.Path
Patched: 0.23.4 — 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-74) exists in org.http4s:http4s-client_2.12. Attackers reach the vulnerable code path via Header.name without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of org.http4s:http4s-client_2.12. Attack surface: Header.name / Header.value / Status.reason / Uri.Path.

🔥 Severity

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

🔧 How to fix

Update to 0.23.4.

🛡️ 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
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで org.http4s:http4s-client_2.12 を使っているサービスとバージョンを洗い出す。
2
Apply patch patch
```
Upgrade org.http4s:http4s-client_2.12 to 0.23.4
```
ステージング環境で 0.23.4 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
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。