# Cwe 732 Improper File Permissions

> Use this skill when you need to remediate CWE-732 (Improper File Permissions) vulnerabilities in Java code. Triggers on SAST findings, security reviews, or when fixing improper file permissions issues.

- Skill: `developerscoffee/cwe-732-improper-file-permissions` (Agent Skill)
- Install (CLI): `npx skillmds@latest add developerscoffee/cwe-732-improper-file-permissions`
- Raw SKILL.md: https://api.skillmd.com/api/skills/developerscoffee/cwe-732-improper-file-permissions/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: MIT
- Author: DevelopersCoffee (https://skillmd.com/u/developerscoffee)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/developerscoffee/cwe-732-improper-file-permissions

---


# CWE-732 Improper File Permissions

## Description

Improper File Permissions

Reference:
https://cwe.mitre.org/data/definitions/732.html


**OWASP Category**: A01:2021 – Broken Access Control


---

## Vulnerable Pattern


### ❌ Example 1: Vulnerable Pattern

```java
// VULNERABLE: World-readable/writable permissions
File configFile = new File("/app/config/secrets.conf");
configFile.setReadable(true, false);   // World readable!
configFile.setWritable(true, false);   // World writable!
configFile.setExecutable(true, false); // World executable!

// VULNERABLE: 777 permissions
Set<PosixFilePermission> perms = PosixFilePermissions.fromString("rwxrwxrwx");
Files.setPosixFilePermissions(path, perms);
```


**Why it's vulnerable:** This pattern is vulnerable to Improper File Permissions




---

## Deterministic Fix


### ✅ Secure Implementation: Secure Implementation

```java
// SECURE: Owner-only permissions (600 for files, 700 for directories)
Path secretFile = Paths.get("/app/config/secrets.conf");

// Set 600 (owner read/write only)
Set<PosixFilePermission> ownerOnly = EnumSet.of(
    PosixFilePermission.OWNER_READ,
    PosixFilePermission.OWNER_WRITE
);
Files.setPosixFilePermissions(secretFile, ownerOnly);

// For directories: 700 (owner rwx only)
Set<PosixFilePermission> dirPerms = EnumSet.of(
    PosixFilePermission.OWNER_READ,
    PosixFilePermission.OWNER_WRITE,
    PosixFilePermission.OWNER_EXECUTE
);
Files.setPosixFilePermissions(Paths.get("/app/config"), dirPerms);

// Create file with restricted permissions atomically
FileAttribute<Set<PosixFilePermission>> attr =
    PosixFilePermissions.asFileAttribute(ownerOnly);
Files.createFile(secretFile, attr);
```


**Why it's secure:** Implements proper protection against Improper File Permissions




---

## Detection Pattern

Look for these patterns in your codebase:


```bash
# Find permissive file operations
grep -rn "setReadable.*false\\|setWritable.*false\\|rwxrwxrwx" --include="*.java"
```



---

## Remediation Steps


1. Use 600 permissions for sensitive files

2. Use 700 permissions for sensitive directories

3. Avoid setReadable/setWritable with 'false' second param

4. Create files with restricted permissions atomically


---

## Key Imports

```java

import java.nio.file.attribute.PosixFilePermission;

import java.nio.file.attribute.PosixFilePermissions;

import java.nio.file.Files;

```

---

## Verification

After remediation:


- Run SAST scanner to confirm vulnerability is resolved

- Review all instances of the vulnerable pattern

- Add unit tests that verify the secure implementation

- Check for similar patterns in related code


---

## Trigger Examples

```
Fix CWE-732 vulnerability
Resolve Improper File Permissions issue
Secure this Java code against improper file permissions
SAST reports CWE-732
```

---

## Common Vulnerable Locations

| Layer | Files | Patterns |
|-------|-------|----------|

| Controller | `*Controller.java` | User input handling |

| Service | `*Service.java` | Business logic |

| Repository | `*Repository.java` | Data access |


---

## References


- [CWE-732: Improper Permission Assignment](https://cwe.mitre.org/data/definitions/732.html)


---

**Source**: Generated by [Java CWE Security Skills Generator](https://github.com/DevelopersCoffee/java-cwe-security-skills)
**Last Updated**: 2026-03-07