Information Disclosure in io.swagger:swagger-codegen (CVE-2021-21364)
Summary
Vulnerability in io.swagger:swagger-codegen (CVE-2021-21364). Confidential information can be exposed externally. Exploitable via umask. Mitigation: upgrade to 2.4.19 or later.
Original description
The description as published by the source.
swagger-codegen is an open-source project which contains a template-driven engine to generate documentation, API clients and server stubs in different languages by parsing your OpenAPI / Swagger definition. In swagger-codegen before version 2.4.19, on Unix-Like systems, the system temporary directory is shared between all local users. When files/directories are created, the default umask settings for the process are respected. As a result, by default, most processes/apis will create files/directories with the permissions -rw-r--r-- and drwxr-xr-x respectively, unless an API that explicitly sets safe file permissions is used. Because this vulnerability impacts generated code, the generated code will remain vulnerable until fixed manually! This vulnerability is fixed in version 2.4.19. Note this is a distinct vulnerability from CVE-2021-21363.
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-2021-21364 has been found in io.swagger:swagger-codegen.
Attackers can target a specific entry point like umask over the network to misuse the product.
Confidential information can be exposed externally.
What to do: upgrade io.swagger:swagger-codegen to 2.4.19 or later.
If unsure, ask your IT team or search "io.swagger:swagger-codegen CVE-2021-21364" on the vendor's site.
CVE-2021-21364 (io.swagger:swagger-codegen) — CWE-200
Attack vector: local / no user interaction
Attack surface: umask
Patched: 2.4.19 — 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.
Information disclosure (CWE-200) exists in io.swagger:swagger-codegen. Attackers reach the vulnerable code path via umask.
Check the vendor advisory for the affected versions of io.swagger:swagger-codegen. Attack surface: umask.
Severity: ?. Confidential information can be exposed externally.
Update to 2.4.19.
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.swagger:swagger-codegen 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.swagger:swagger-codegen to 2.4.19ステージング環境で 2.4.19 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