CVE-2021-42717

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

Alt Linux, Debian, Linuxmint, Modsecurity, Nginx, Ubuntu

Owasp Modsecurity

< 3.0.6

Trustwave Modsecurity

< 2.9.5

Fix

Available

CVSS 3.1

7.5 HIGH

EPSS

3.1% (87th percentile)

Weakness

CWE-674

NVD status

Modified

Published

2021-12-07