Vulnerability in io.ktor:ktor-client-cio (CVE-2020-5207)
Summary
Vulnerability in io.ktor:ktor-client-cio (CVE-2020-5207). Data can be tampered with by attackers. Mitigation: upgrade to 1.3.0 or later.
Original description
The description as published by the source.
In Ktor before 1.3.0, request smuggling is possible when running behind a proxy that doesn't handle Content-Length and Transfer-Encoding properly or doesn't handle \n as a headers separator.
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-2020-5207 has been found in io.ktor:ktor-client-cio.
Data can be tampered with by attackers.
What to do: upgrade io.ktor:ktor-client-cio to 1.3.0 or later.
If unsure, ask your IT team or search "io.ktor:ktor-client-cio CVE-2020-5207" on the vendor's site.
CVE-2020-5207 (io.ktor:ktor-client-cio) — CWE-444
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.3.0 — 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.
A vulnerability (CWE-444) exists in io.ktor:ktor-client-cio.
Check the vendor advisory for the affected versions of io.ktor:ktor-client-cio.
Severity: ?. Data can be tampered with by attackers.
Update to 1.3.0.
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. Audit SBOM/dependencies 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
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで io.ktor:ktor-client-cio を使っているサービスとバージョンを洗い出す。
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2Apply patch patch
Upgrade io.ktor:ktor-client-cio to 1.3.0ステージング環境で 1.3.0 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。
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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
- patch github.com