Vulnerability in Akka HTTP (CVE-2021-42697)

Summary

Vulnerability in Akka HTTP (CVE-2021-42697). Risk of unauthorized operations or information disclosure. Exploitable via User-Agent header.

Original description

The description as published by the source.

Akka HTTP 10.1.x before 10.1.15 and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.

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-2021-42697 has been found in Akka HTTP.
Attackers can target a specific entry point like User-Agent header over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Akka HTTP CVE-2021-42697" on the vendor's site.

CVE-2021-42697 (Akka HTTP)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: User-Agent header
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) exists in Akka HTTP. Attackers reach the vulnerable code path via User-Agent header without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of Akka HTTP. Attack surface: User-Agent header.

🔥 Severity

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

🔧 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
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで Akka HTTP を使っているサービスとバージョンを洗い出す。
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。

References

advisory akka.io
advisory akka.io
advisory akka.io
advisory doc.akka.io
report packetstormsecurity.com