CVE-2021-43836

PHP file inclusion in the Sulu admin panel

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

Overwrite the service sulu_route.generator.expression_token_provider and wrap the translator before passing it to the expression language.

References

Are there any links users can visit to find out more?

Currently not.

For more information

If you have any questions or comments about this advisory:

• Open an issue in example link to repo
• Email us at example email address

What kind of vulnerability is it? Who is impacted?

An attacker can read arbitrary local files via a PHP file include. In a default configuration this also leads to remote code execution.

• Compromised components: Arbitrary file read on the server, (Potential) Remote code execution
• Exploitation pre-requisite: User account on the backend

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2021-43836 has a CVSS score of 8.5 (High). The vector is network-reachable, low 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 (1.6.44, 2.2.18, 2.3.8, 2.4.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Has the problem been patched? What versions should users upgrade to?

The problem is patched with the Versions 1.6.44, 2.2.18, 2.3.8, 2.4.0

1. What is CVE-2021-43836? CVE-2021-43836 is a high-severity path traversal vulnerability in sulu/sulu (composer), affecting versions < 1.6.44. It is fixed in 1.6.44, 2.2.18, 2.3.8, 2.4.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2021-43836? CVE-2021-43836 has a CVSS score of 8.5 (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 sulu/sulu are affected by CVE-2021-43836? sulu/sulu (composer) versions < 1.6.44 is affected.
4. Is there a fix for CVE-2021-43836? Yes. CVE-2021-43836 is fixed in 1.6.44, 2.2.18, 2.3.8, 2.4.0. Upgrade to this version or later.
5. Is CVE-2021-43836 exploitable, and should I be worried? Whether CVE-2021-43836 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-2021-43836 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-2021-43836?
   • Upgrade sulu/sulu to 1.6.44 or later
   • Upgrade sulu/sulu to 2.2.18 or later
   • Upgrade sulu/sulu to 2.3.8 or later
   • Upgrade sulu/sulu to 2.4.0 or later

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