cvedb.io
CVE-2021-42717
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2021-12-07T22:15:06.950 · Last modified 2026-06-17T04:10:00.253

Summary

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.

Affected products

owasp — modsecurity

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.