// For flags

CVE-2021-32792

XSS vulnerability when using OIDCPreservePost On in mod_auth_openidc

Severity Score

6.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In mod_auth_openidc before version 2.4.9, there is an XSS vulnerability in when using `OIDCPreservePost On`.

mod_auth_openidc es un módulo de autenticación/autorización para el servidor HTTP Apache versión 2.x que funciona como OpenID Connect Relying Party, autenticando a usuarios contra un proveedor de OpenID Connect. En mod_auth_openidc versiones anteriores a 2.4.9, se presenta una vulnerabilidad de tipo XSS cuando se usa el parámetro "OIDCPreservePost On"

A flaw was found in mod_auth_openidc. When mod_auth_openidc is configured with `OIDCPreservePost On` it is possible to trigger a cross site scripting(XSS) vulnerability that could be used by a remote attacker to execute code on the browser of the victim user. The highest threat from this flaw is to data confidentiality and integrity.

An update that fixes four vulnerabilities is now available. This update for apache2-mod_auth_openidc fixes the following issues. Format string bug via hiredis open redirect in logout functionality Hardcoded static IV and AAD with a reused key in AES GCM encryption XSS when using OIDCPreservePost On.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-05-12 CVE Reserved
  • 2021-07-26 CVE Published
  • 2024-08-03 CVE Updated
  • 2025-07-04 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Openidc
Search vendor "Openidc"
 Mod Auth Openidc
Search vendor "Openidc" for product "Mod Auth Openidc"
 < 2.4.9
Search vendor "Openidc" for product "Mod Auth Openidc" and version " < 2.4.9"
-
Affected
in Apache
Search vendor "Apache"
 Http Server
Search vendor "Apache" for product "Http Server"
 >= 2.0.0 <= 2.4.48
Search vendor "Apache" for product "Http Server" and version " >= 2.0.0 <= 2.4.48"
-
Safe
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 34
Search vendor "Fedoraproject" for product "Fedora" and version "34"
-
Affected