CVE-2021-41170

Insecure Inherited Permissions in neoan3-apps/template

Workarounds

Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade.

References

As a possible exploit is relatively easy to achieve, I will not share steps to reproduce the issue for now.

For more information

If you have any questions or comments about this advisory:

• Open an issue in our repo

Versions prior 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously.

In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible.

A file, directory, or other resource is assigned permissions that allow broader access than intended. Typical impact: unauthorized read, modification, or execution of the resource.

CVE-2021-41170 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.1.1); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Version 1.1.1 has addressed this vulnerability.

$params = [
   'reverse' => fn($input) => strrev($input),    // <-- no longer possible with version ~1.1.1
   'value' => 'My website' 
]
TemplateFunctions::registerClosure('reverse', fn($input) => strrev($input));  // <-- still possible (and nicely isolated)
Template::embrace('<h1>{{reverse(value)}}</h1>', $params);

1. What is CVE-2021-41170? CVE-2021-41170 is a high-severity incorrect permission assignment for critical resource vulnerability in neoan3-apps/template (composer), affecting versions < 1.1.1. It is fixed in 1.1.1. A file, directory, or other resource is assigned permissions that allow broader access than intended.
2. How severe is CVE-2021-41170? CVE-2021-41170 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of neoan3-apps/template are affected by CVE-2021-41170? neoan3-apps/template (composer) versions < 1.1.1 is affected.
4. Is there a fix for CVE-2021-41170? Yes. CVE-2021-41170 is fixed in 1.1.1. Upgrade to this version or later.
5. Is CVE-2021-41170 exploitable, and should I be worried? Whether CVE-2021-41170 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2021-41170 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2021-41170? Upgrade neoan3-apps/template to 1.1.1 or later.