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DEBIAN-CVE-2021-42717

DEBIAN-CVE-2021-42717 PUBLISHED CVSS 7.5 HIGH

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.

Risk Scores

CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Products

VendorProductVersions
Debian:11modsecurity-apache0, 2.9.3-3, 2.9.3-3
Debian:14modsecurity0, 0, 0
Debian:11modsecurity3.0.4-2, 3.0.6-1, 3.0.8-2
Debian:13modsecurity0, 0, 0
Debian:12modsecurity0, 0, 0
Debian:13modsecurity-apache0, 0, 0
Debian:12modsecurity-apache0, 0, 0
Debian:14modsecurity-apache0, 0, 0

Timeline

  • Dec 7, 2021 CVE Published
  • Apr 28, 2026 CVE Updated
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