RHEL 7 : mod_auth_openidc (Unpatched Vulnerability)

medium Nessus Plugin ID 195625

Synopsis

The remote Red Hat 7 host is affected by multiple vulnerabilities that will not be patched.

Description

The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

- mod_auth_openidc: open redirect due to target_link_uri parameter not validated (CVE-2021-39191)

- mod_auth_openidc: Open Redirect in oidc_validate_redirect_url() using tab character (CVE-2022-23527)

- 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 versions prior to 2.4.9, `oidc_validate_redirect_url()` does not parse URLs the same way as most browsers do. As a result, this function can be bypassed and leads to an Open Redirect vulnerability in the logout functionality. This bug has been fixed in version 2.4.9 by replacing any backslash of the URL to redirect with slashes to address a particular breaking change between the different specifications (RFC2396 / RFC3986 and WHATWG). As a workaround, this vulnerability can be mitigated by configuring `mod_auth_openidc` to only allow redirection whose destination matches a given regular expression.
(CVE-2021-32786)

- 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, the AES GCM encryption in mod_auth_openidc uses a static IV and AAD. It is important to fix because this creates a static nonce and since aes-gcm is a stream cipher, this can lead to known cryptographic issues, since the same key is being reused. From 2.4.9 onwards this has been patched to use dynamic values through usage of cjose AES encryption routines. (CVE-2021-32791)

- mod_auth_openidc is an OpenID Certified authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. In affected versions missing input validation on mod_auth_openidc_session_chunks cookie value makes the server vulnerable to a denial of service (DoS) attack. An internal security audit has been conducted and the reviewers found that if they manipulated the value of the mod_auth_openidc_session_chunks cookie to a very large integer, like 99999999, the server struggles with the request for a long time and finally gets back with a 500 error.
Making a few requests of this kind caused our server to become unresponsive. Attackers can craft requests that would make the server work very hard (and possibly become unresponsive) and/or crash with minimal effort. This issue has been addressed in version 2.4.15.2. Users are advised to upgrade. There are no known workarounds for this vulnerability. (CVE-2024-24814)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

Solution

The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation guidance.

Plugin Details

Severity: Medium

ID: 195625

File Name: redhat_unpatched-mod_auth_openidc-rhel7.nasl

Version: 1.0

Type: local

Agent: unix

Published: 5/11/2024

Updated: 5/11/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.8

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2021-39191

CVSS v3

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 5.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2022-23527

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:redhat:enterprise_linux:mod_auth_openidc

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 7/22/2021

Reference Information

CVE: CVE-2021-32786, CVE-2021-32791, CVE-2021-39191, CVE-2022-23527, CVE-2024-24814