RHSA-2025:4576

Jinja is an extensible templating engine. Prior to 3.1.5, An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox. This vulnerability is fixed in 3.1.5.

graphql-ruby is a Ruby implementation of GraphQL. Starting in version 1.11.5 and prior to versions 1.11.8, 1.12.25, 1.13.24, 2.0.32, 2.1.14, 2.2.17, and 2.3.21, loading a malicious schema definition in `GraphQL::Schema.from_introspection` (or `GraphQL::Schema::Loader.load`) can result in remote code execution. Any system which loads a schema by JSON from an untrusted source is vulnerable, including those that use GraphQL::Client to load external schemas via GraphQL introspection. Versions 1.11.8, 1.12.25, 1.13.24, 2.0.32, 2.1.14, 2.2.17, and 2.3.21 contain a patch for the issue.

Rack provides an interface for developing web applications in Ruby. Prior to versions 2.2.13, 3.0.14, and 3.1.12, `Rack::Static` can serve files under the specified `root:` even if `urls:` are provided, which may expose other files under the specified `root:` unexpectedly. The vulnerability occurs because `Rack::Static` does not properly sanitize user-supplied paths before serving files. Specifically, encoded path traversal sequences are not correctly validated, allowing attackers to access files outside the designated static file directory. By exploiting this vulnerability, an attacker can gain access to all files under the specified `root:` directory, provided they are able to determine then path of the file. Versions 2.2.13, 3.0.14, and 3.1.12 contain a patch for the issue. Other mitigations include removing usage of `Rack::Static`, or ensuring that `root:` points at a directory path which only contains files which should be accessed publicly. It is likely that a CDN or similar static file server would also mitigate the issue.