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.

CVSS v3.0 7.5 HIGH
CVSS v2.0 5.0 MEDIUM

7.5^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

5.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:N/C:N/I:N/A:P

Exploitability : 10.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

References

Link	Resource
https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/	Exploit Mitigation Vendor Advisory
https://www.debian.org/security/2021/dsa-5023	Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html
https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:trustwave:modsecurity::::::::
	cpe:2.3:a:trustwave:modsecurity::::::::

Configuration 2 (hide)

OR	cpe:2.3:a:f5:nginx_modsecurity_waf:r25:::::::*
	cpe:2.3:a:f5:nginx_modsecurity_waf:r24:::::::*

Configuration 3 (hide)

OR	cpe:2.3:o:debian:debian_linux:10.0:::::::*
	cpe:2.3:o:debian:debian_linux:11.0:::::::*

Information

Published : 2021-12-07 22:15

Updated : 2022-06-02 14:15

NVD link : CVE-2021-42717

Mitre link : CVE-2021-42717

JSON object : View

Products Affected

debian

debian_linux

f5

nginx_modsecurity_waf

trustwave

modsecurity

CWE

CWE-674

Uncontrolled Recursion

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