Summary
Deserialization of Untrusted Data in Codeigniter4
Workarounds
Do not use:
old()and form_helperRedirectResponse::withInput()andredirect()->withInput()
References
For more information
If you have any questions or comments about this advisory:
- Open an issue in codeigniter4/CodeIgniter4
- Email us at SECURITY.md
Impact
Deserialization of Untrusted Data was found in the old() function in CodeIgniter4.
Remote attackers may inject auto-loadable arbitrary objects with this vulnerability,
and possibly execute existing PHP code on the server.
We are aware of a working exploit, which can lead to SQL injection.
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
CVE-2022-21647 has a CVSS score of 7.7 (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 (4.1.6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Upgrade to v4.1.6 or later.
Frequently Asked Questions
- What is CVE-2022-21647? CVE-2022-21647 is a high-severity insecure deserialization vulnerability in codeigniter4/framework (composer), affecting versions < 4.1.6. It is fixed in 4.1.6. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
- How severe is CVE-2022-21647? CVE-2022-21647 has a CVSS score of 7.7 (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.
- Which versions of codeigniter4/framework are affected by CVE-2022-21647? codeigniter4/framework (composer) versions < 4.1.6 is affected.
- Is there a fix for CVE-2022-21647? Yes. CVE-2022-21647 is fixed in 4.1.6. Upgrade to this version or later.
- Is CVE-2022-21647 exploitable, and should I be worried? Whether CVE-2022-21647 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
- What actually determines whether CVE-2022-21647 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.
- How do I fix CVE-2022-21647? Upgrade
codeigniter4/frameworkto 4.1.6 or later.