Modernize and secure temp file creation
pixee:java/upgrade-tempfile-to-nio​
Importance | Review Guidance | Requires Scanning Tool |
---|---|---|
MEDIUM | Merge Without Review | No |
This change replaces the usage of java.io.File#createTempFile
with java.nio.file.Files#createTempFile
which has more secure attributes.
The java.io.File#createTempFile()
method creates a file that is world-readable and world-writeable, which is almost never necessary. Also, the file created is placed in a predictable directory (e.g., /tmp
). Having predictable file names, locations, and will lead to many types of vulnerabilities. History has shown that this insecure pattern can lead to information leakage, privilege escalation and even code execution.
Our changes look something like this:
+ import java.nio.file.Files;
...
- File txtFile = File.createTempFile("acme", ".txt");
+ File txtFile = Files.createTempFile("acme", ".txt").toFile();
References​
- https://cwe.mitre.org/data/definitions/378.html
- https://docs.fluidattacks.com/criteria/vulnerabilities/160/
- https://github.com/apache/druid/issues/11130
- https://owasp.org/www-community/vulnerabilities/Insecure_Temporary_File
- https://nvd.nist.gov/vuln/detail/CVE-2022-41954
- https://www.cvedetails.com/vulnerability-list/cwe-378/vulnerabilities.html