// For flags

CVE-2022-39957

Response body bypass in OWASP ModSecurity Core Rule Set via a specialy crafted charset in the HTTP Accept header

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass. A client can issue an HTTP Accept header field containing an optional "charset" parameter in order to receive the response in an encoded form. Depending on the "charset", this response can not be decoded by the web application firewall. A restricted resource, access to which would ordinarily be detected, may therefore bypass detection. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.

OWASP ModSecurity Core Rule Set (CRS) esta afectado por una omisión del cuerpo de respuesta. Un cliente puede emitir un campo de encabezado HTTP Accept que contenga un parámetro opcional "charset" para recibir la respuesta de forma codificada. En función del "charset", esta respuesta puede no ser descodificada por el firewall de la aplicación web. Por lo tanto, un recurso restringido, cuyo acceso sería detectado normalmente, puede omitir la detección. Están afectadas las versiones 3.0.x y 3.1.x del CRS heredado, así como las versiones 3.2.1 y 3.3.2 actualmente soportadas. Es recomendado a integradores y usuarios actualizar a versiones 3.2.2 y 3.3.3 respectivamente

*Credits: @Karel_Origin (Karel Knibbe)
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-09-05 CVE Reserved
  • 2022-09-20 CVE Published
  • 2024-04-12 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-116: Improper Encoding or Escaping of Output
  • CWE-693: Protection Mechanism Failure
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Owasp
Search vendor "Owasp"
 Owasp Modsecurity Core Rule Set
Search vendor "Owasp" for product "Owasp Modsecurity Core Rule Set"
 >= 3.0.0 < 3.2.2
Search vendor "Owasp" for product "Owasp Modsecurity Core Rule Set" and version " >= 3.0.0 < 3.2.2"
-
Affected
Owasp
Search vendor "Owasp"
 Owasp Modsecurity Core Rule Set
Search vendor "Owasp" for product "Owasp Modsecurity Core Rule Set"
 >= 3.3.0 < 3.3.3
Search vendor "Owasp" for product "Owasp Modsecurity Core Rule Set" and version " >= 3.3.0 < 3.3.3"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 35
Search vendor "Fedoraproject" for product "Fedora" and version "35"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 36
Search vendor "Fedoraproject" for product "Fedora" and version "36"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 37
Search vendor "Fedoraproject" for product "Fedora" and version "37"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected