Versions of the package io.pebbletemplates:pebble from 0 and before 4.1.0 are vulnerable to External Control of File Name or Path via the include tag. A high privileged attacker can access sensitive local files by crafting malicious notification templates that leverage this tag to include files like /etc/passwd or /proc/1/environ. Workaround This vulnerability can be mitigated by disabling the include macro in Pebble Templates: java new PebbleEngine.Builder() .registerExtensionCustomizer(new DisallowExtensionCustomizerBuilder() .disallowedTokenParserTags(List.of("include")) .build()) .build();

Affected: Maven: io.pebbletemplates:pebble

### Summary

If untrusted user input is used to dynamically create a `PebbleTemplate` with the method `PebbleEngine#getLiteralTemplate`, then an attacker can include arbitrary local files from the file system into the generated template, leaking potentially sensitive information into the output of `PebbleTemplate#evaluate`. This is done via the `include` macro.

### Details

The `include` macro calls `PebbleTempateImpl#resolveRelativePath` with the `relativePath` argument passed within the template:

Example template: ``` {% include [relativePath] %} ``` When `resolveRelativePath` is called, the `relativePath` is resolved against the `PebbleTemplateImpl.name` variable.

```java /** * This method resolves the given relative path based on this template file path. * * @param relativePath the path which should be resolved. * @return the resolved path. */ public String resolveRelativePath(String relativePath) { String resolved = this.engine.getLoader().resolveRelativePath(relativePath, this.name); if (resolved == null) { return relativePath; } else { return resolved; } } ``` https://github.com/PebbleTemplates/pebble/blob/82ad7fcf9e9eaa45ee82ae3335a1409d19c10263/pebble/src/main/java/io/pebbletemplates/pebble/template/PebbleTemplateImpl.java#L380

Unfortunately, when the template is created from a string, as is the case when `PebbleEngine#getLiteralTemplate` is used, the `PebbleTemplateImpl.name` variable is actually the entirety of…