insecure-temp-files-anti-pattern
Insecure Temp Files Anti-Pattern
Severity: Medium
Summary
Insecure temporary file creation exposes three attack vectors: predictable file names enabling symlink attacks, insecure permissions allowing unauthorized access, and missing cleanup leaving sensitive data on disk. Attackers exploit these to read sensitive data, inject malicious content, or cause denial of service. AI-generated code frequently suggests simplistic file handling vulnerable to these attacks.
The Anti-Pattern
Never create temporary files without securing their location, naming, permissions, and lifecycle management.
1. Predictable File Names
Using a predictable name for a temporary file creates a race condition. An attacker can guess the file name and create a symbolic link (symlink) at that location pointing to a sensitive system file. When the application writes to its "temporary" file, it is actually overwriting the linked file.