Iris is a web collaborative platform aiming to help incident responders sharing technical details during investigations. Due to an improper setup of Jinja2 environment, reports generation in iris-web is prone to a Server Side Template Injection (SSTI). Successful exploitation of the vulnerability can lead to an arbitrary Remote Code Execution. An authenticated administrator has to upload a crafted report template containing the payload. Upon generation of a report based on the weaponized report, any user can trigger the vulnerability. The vulnerability is patched in IRIS v2.4.6. No workaround is available. It is recommended to update as soon as possible. Until patching, review the report templates and keep the administrative privileges that include the upload of report templates limited to dedicated users.
The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.
Many web applications use template engines that allow developers to insert externally-influenced values into free text or messages in order to generate a full web page, document, message, etc. Such engines include Twig, Jinja2, Pug, Java Server Pages, FreeMarker, Velocity, ColdFusion, Smarty, and many others - including PHP itself. Some CMS (Content Management Systems) also use templates. Template engines often have their own custom command or expression language. If an attacker can influence input into a template before it is processed, then the attacker can invoke arbitrary expressions, i.e. perform injection attacks. For example, in some template languages, an attacker could inject the expression “{{7*7}}” and determine if the output returns “49” instead. The syntax varies depending on the language. In some cases, XSS-style attacks can work, which can obscure the root cause if the developer does not closely investigate the root cause of the error. Template engines can be used on the server or client, so both “sides” could be affected by injection. The mechanisms of attack or the affected technologies might be different, but the mistake is fundamentally the same.