Escape Jelly (instance security hardening)

  • Release version: Washingtondc
  • Updated February 1, 2024
  • 1 minute to read

    • Use the glide.ui.escape_all_script property to force escape of all scripts injected into Jelly.

    It escapes all the JS and HTML strings included in <j:jelly> ... </j:jelly> on input forms, consoles, or API calls before they are written to the output stream, preventing several XSS issues from occurring.

    More information

    Attribute Description
    Property name glide.ui.escape_all_script
    Configuration type System Properties (/sys_properties_list.do)
    Configure in Instance Security Center Yes
    Purpose

    If the property is not set to true, developers have to perform several steps on each custom Jelly script to prevent XSS issues. These steps include locating the Jelly variables being sent to output stream to render on web pages, and performing escaping on each of the following tags:

    $â {JS:expression}

    $â {HTML:expression}

    OR

    $â {JS,HTML:expression}
    Recommended value true
    Functional ImpactThis remediation enforces Jelly escaping at the parser level. It can have a functionality impact on user interaction with the resulting data.
    Security risk (High) Input validation has to occur on all the user input being entered on the application. By doing so, injection attacks against the platform can be defended and protected.
    Workaround

    The UI may be affected because some of the scripts and HTML tags designed for rendering on a web page may appear broken. This remediation sends the output encoded page to the browser to render.

    For example, instead of 'my string here', it might display '<u>my string here</u> as the <u> tag was properly escaped. In this case, to prevent escaping, add the NOESC prefix to Jelly expression to prevent JS escaping. For example:
    • Before: ($[jvar_context_menus]);
    • After: ($[NOESC:jvar_context_menus]);
    • Before: $[jvar_ui_policy_scripts]
    • After: $[NOESC:jvar_ui_policy_scripts]
    References

    High Security Settings

    Jelly tags

    To learn more about adding or creating a system property, see Add a system property.