CVE-2021-42717
7.5 · HIGHOverview
CVE-2021-42717 is a high-severity vulnerability affecting owasp modsecurity. It was published on December 7, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
ModSecurity 3.x through 3.0.5 mishandles excessively nested JSON objects. Crafted JSON objects with nesting tens-of-thousands deep could result in the web server being unable to service legitimate requests. Even a moderately large (e.g., 300KB) HTTP request can occupy one of the limited NGINX worker processes for minutes and consume almost all of the available CPU on the machine. Modsecurity 2 is similarly vulnerable: the affected versions include 2.8.0 through 2.9.4.
Remediation
Check the references section for vendor advisories and patches from owasp. Update modsecurity to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| owasp | modsecurity | >= 3.0.0, < 3.0.6 | Affected |
| trustwave | modsecurity | >= 2.0.0, < 2.9.5 | Affected |
References
Frequently Asked Questions
What is CVE-2021-42717?
CVE-2021-42717 is a high-severity vulnerability affecting owasp modsecurity. It was published on December 7, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2021-42717?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-42717?
Check the references section for vendor advisories and patches from owasp. Update modsecurity to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-42717?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-42717 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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