insecure-dir-creation.yaml

rules:
  - id: insecure-dir-creation
    message: A file or directory `$FI` with restrictive permissions was created 
      without checking if `$FI` already exists. Creating a file or directory without 
      checking if it exists first will not overwrite permission
    languages: [go]
    severity: WARNING
    metadata:
      cwe:
        - "CWE-59: Improper Link Resolution Before File Access ('Link Following')"
        - "CWE-281: Improper Preservation of Permissions"
      category: security
      subcategory:
        - vuln
      confidence: HIGH
      impact: MEDIUM
      likelihood: MEDIUM
      technology:
        - go
      description: "Insecure handling of file and directory writes"
      references:
        - https://github.com/golang/go/issues/35711
    patterns:
      - pattern-either:
          - pattern: ioutil.WriteFile($PATH, ..., $PERM)
          - pattern: os.WriteFile($PATH, ..., $PERM)
          - pattern: os.MkdirAll($PATH, $PERM)
          - pattern: os.Mkdir($PATH, $PERM)
      - pattern-not-inside: |
          if ..., $ERR := os.Stat($PATH); os.IsNotExist($ERR) {
            ...
          }
      - pattern-not-inside: |
          $FI, $ERR := os.Stat($PATH)
          if $ERR != nil && os.IsNotExist(...) {
            ...
          }
      - pattern-not-inside: |
          $FI, $ERR := os.Stat($PATH)
          if $ERR != nil && os.IsNotExist(...) {
            ...
          }
      - metavariable-comparison:
          comparison: int($PERM) < 0o600 or int($PERM) == 0o700
          metavariable: $PERM