mako-templates (S702)

Derived from the flake8-bandit linter.

What it does

Checks for uses of the mako templates.

Why is this bad?

Mako templates allow HTML and JavaScript rendering by default, and are inherently open to XSS attacks. Ensure variables in all templates are properly sanitized via the n, h or x flags (depending on context). For example, to HTML escape the variable data, use ${ data |h }.

Example

from mako.template import Template

Template("hello")

Use instead:

from mako.template import Template

Template("hello |h")

References

• Mako documentation
• OpenStack security: Cross site scripting XSS
• Common Weakness Enumeration: CWE-80