CVE-2021-21363

MEDIUM

swagger-codegen < 2.4.19 - Local Privilege Escalation via Temporary Directory Race Condition

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2021-21363. PoCs published by dawetmaster, andikahilmy.

AI-analyzed exploit summary This repository contains a vulnerable version of Swagger Codegen (CVE-2021-21363), which is susceptible to arbitrary code execution during code generation. The repository includes build scripts and configuration files to reproduce the vulnerability.

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's temporary directory is shared between all users on that system. A collocated user can observe the process of creating a temporary sub directory in the shared temporary directory and race to complete the creation of the temporary subdirectory. This vulnerability is local privilege escalation because the contents of the `outputFolder` can be appended to by an attacker. As such, code written to this directory, when executed can be attacker controlled. For more details refer to the referenced GitHub Security Advisory. This vulnerability is fixed in version 2.4.19. Note this is a distinct vulnerability from CVE-2021-21364.

Exploits (2)

nomisec WORKING POC
by dawetmaster · poc
https://github.com/dawetmaster/CVE-2021-21363-swagger-codegen-vulnerable

This repository contains a vulnerable version of Swagger Codegen (CVE-2021-21363), which is susceptible to arbitrary code execution during code generation. The repository includes build scripts and configuration files to reproduce the vulnerability.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Swagger Codegen
No auth needed
Prerequisites: Vulnerable version of Swagger Codegen · Ability to trigger code generation with malicious input
devstral-2 · analyzed Mar 14, 2026 Full analysis →
nomisec WORKING POC
by andikahilmy · poc
https://github.com/andikahilmy/CVE-2021-21363-swagger-codegen-vulnerable

This repository contains a vulnerable version of Swagger Codegen (CVE-2021-21363) with multiple language-specific scripts to generate and test petstore samples. The presence of build scripts and CI configurations suggests it is a functional exploit environment for demonstrating the vulnerability.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Swagger Codegen < 3.0.23
No auth needed
Prerequisites: Access to a vulnerable Swagger Codegen instance · Ability to provide malicious input to the code generation process
devstral-2 · analyzed Feb 18, 2026 Full analysis →

Scores

CVSS v3 5.3
EPSS 0.0004
EPSS Percentile 14.0%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N

Details

CWE
CWE-378 CWE-379
Status published
Products (2)
io.swagger/swagger-codegen 0 - 2.4.19Maven
smartbear/swagger-codegen < 2.4.19
Published Mar 11, 2021
Tracked Since Feb 18, 2026