mcp-server-semgrep/semgrep-rules/python/flask/security/xss/audit/template-unescaped-with-safe.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: template-unescaped-with-safe
  message: >-
    Detected a segment of a Flask template where autoescaping is explicitly
    disabled with '| safe' filter. This allows rendering of raw HTML
    in this segment. Ensure no user data is rendered here, otherwise this
    is a cross-site scripting (XSS) vulnerability.
  metadata:
    cwe:
    - "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
    owasp:
    - A07:2017 - Cross-Site Scripting (XSS)
    - A03:2021 - Injection
    references:
    - https://flask.palletsprojects.com/en/1.1.x/security/#cross-site-scripting-xss
    category: security
    technology:
    - flask
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: MEDIUM
    confidence: LOW
  languages:
  - regex
  paths:
    include:
    - '*.html'
  severity: WARNING
  pattern-regex: '{{.*?\|\s*safe(\s*}})?'