CVE-2021-21429 | Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI Generator Maven plugin

OpenAPI Generator allows generation of API client libraries, server stubs, documentation and configuration automatically given an OpenAPI Spec. Using `File.createTempFile` in JDK will result in creating and using insecure temporary files that can leave application and system data vulnerable to attacks. OpenAPI Generator maven plug-in creates insecure temporary files during the process. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Published: 2021-04-27 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-21429 is rated Low Risk (20.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-21429

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-17 0.04% 0.05% +0.01%
2 2023-03-07 0.89% 0.04% -0.84%
3 2022-04-01 — 0.89% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21429

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 1.4 [email protected]
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-21429

GitHub Security Advisory for CVE-2021-21429

GHSA-867q-77cc-98mv · Severity: medium · Ecosystem: maven — Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI Generator Maven plugin

OS Trackers for CVE-2021-21429

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2021-21429

Affected software / configurations for CVE-2021-21429

Vendor Product Version Raw CPE
openapi-generator openapi_generator < 5.1.0 cpe:2.3:a:openapi-generator:openapi_generator:*:*:*:*:*:*:*:*

References for CVE-2021-21429

cvelogic Threat Intelligence