GHSA-23X4-M842-FMWF
Vulnerability from github – Published: 2021-05-11 00:04 – Updated: 2023-06-30 20:30Impact
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.
openapi-generator-online creates insecure temporary folders with File.createTempFile during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system.
Vulnerable Code
https://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187
This vulnerability exists due to a race condition between the deletion of the randomly generated temporary file and the creation of the temporary directory.
File outputFolder = File.createTempFile("codegen-", "-tmp"); // Attacker knows the full path of the file that will be generated
// delete the file that was created
outputFolder.delete(); // Attacker sees file is deleted and begins a race to create their own directory before the code generator
// and make a directory of the same name
// SECURITY VULNERABILITY: Race Condition! - Attacker beats the code generator and now owns this directory
outputFolder.mkdir();
Patches
The issue has been patched by changing the underlying logic to use Files.createTempFile and has been released in the v5.1.0 stable version.
This vulnerability has the same root cause as CVE-2021-21363 from the swagger-api/swagger-codegen project as this project and that one both share the same original source tree.
See: https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j
For more information
If you have any questions or comments about this advisory: * Open an issue in OpenAPI Generator Github repo * Email us at security@openapitools.org
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.openapitools:openapi-generator-online"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-21428"
],
"database_specific": {
"cwe_ids": [
"CWE-269",
"CWE-377",
"CWE-378",
"CWE-379",
"CWE-668"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-10T18:52:04Z",
"nvd_published_at": "2021-05-10T19:15:00Z",
"severity": "CRITICAL"
},
"details": "### Impact\n\nOn Unix like systems, the system\u0027s 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.\n\nThis 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.\n\nopenapi-generator-online creates insecure temporary folders with `File.createTempFile` during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system.\n\n### Vulnerable Code\n\nhttps://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187\n\nThis vulnerability exists due to a race condition between the deletion of the randomly generated temporary file and the creation of the temporary directory.\n\n```java\nFile outputFolder = File.createTempFile(\"codegen-\", \"-tmp\"); // Attacker knows the full path of the file that will be generated\n// delete the file that was created\noutputFolder.delete(); // Attacker sees file is deleted and begins a race to create their own directory before the code generator\n// and make a directory of the same name\n// SECURITY VULNERABILITY: Race Condition! - Attacker beats the code generator and now owns this directory\noutputFolder.mkdir();\n```\n\n### Patches\nThe issue has been patched by changing the underlying logic to use `Files.createTempFile` and has been released in the v5.1.0 stable version.\n\nThis vulnerability has the same root cause as CVE-2021-21363 from the `swagger-api/swagger-codegen` project as this project and that one both share the same original source tree.\nSee: https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [OpenAPI Generator Github repo](https://github.com/openAPITools/openapi-generator/)\n* Email us at [security@openapitools.org](mailto:security@openapitools.org)",
"id": "GHSA-23x4-m842-fmwf",
"modified": "2023-06-30T20:30:26Z",
"published": "2021-05-11T00:04:40Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwf"
},
{
"type": "WEB",
"url": "https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21428"
},
{
"type": "WEB",
"url": "https://github.com/OpenAPITools/openapi-generator/pull/8788"
},
{
"type": "PACKAGE",
"url": "https://github.com/OpenAPITools/openapi-generator"
},
{
"type": "WEB",
"url": "https://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI-Generator online generator"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.