CVE-2021-21364: Generated Code Contains Local Information Disclosure Vulnerability

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-03-11 · updated 2026-06-17
Weakness: CWE-200

Description

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.

Affected products

swagger-api swagger-codegen: before 2.4.19 — fixed in 2.4.19

How to fix

Upgrade to a fixed version: swagger-api swagger-codegen 2.4.19. Check the vendor advisory for mitigations.

References

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