CWE-1336: Improper Neutralization of Special Elements Used in a Template 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.
Modes of Introduction
Phase | Note |
---|---|
Architecture and Design | The developer might choose a template engine that makes it easier for programmers to write vulnerable code. |
Implementation | The programmer might not use engine's built-in sandboxes or other capabilities to escape or otherwise prevent template injection from untrusted input. |
Applicable Platforms
Type | Class | Name | Prevalence |
---|---|---|---|
Language | Java | ||
Language | PHP | ||
Language | Python | ||
Language | JavaScript | ||
Language | Interpreted | ||
Operating_system | Not OS-Specific | ||
Technology | AI/ML | ||
Technology | Client Server |
CVEs Published
CVSS Severity
CVSS Severity - By Year
CVSS Base Score
# CVE | Description | CVSS | EPSS | EPSS Trend (30 days) | Affected Products | Weaknesses | Security Advisories | Exploits | PoC | Pubblication Date | Modification Date |
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# CVE | Description | CVSS | EPSS | EPSS Trend (30 days) | Affected Products | Weaknesses | Security Advisories | PoC | Pubblication Date | Modification Date |