SB2021073016 - Fedora 34 update for mod_auth_openidc
Published: July 30, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Open redirect (CVE-ID: CVE-2021-32786)
The vulnerability allows a remote attacker to redirect victims to arbitrary URL.
The vulnerability exists due to improper sanitization of user-supplied data in oidc_validate_redirect_url() function. A remote attacker can create a link that leads to a trusted website, however, when clicked, redirects the victim to arbitrary domain.
Successful exploitation of this vulnerability may allow a remote attacker to perform a phishing attack and steal potentially sensitive information.
2) Use of insufficiently random values (CVE-ID: CVE-2021-32791)
The vulnerability allows a remote attacker to perform a brute-force attack.
The vulnerability exists due to the AES GCM encryption in mod_auth_openidc uses a static IV and AAD, which creates a static nonce. Since aes-gcm is a stream cipher, this can lead to known cryptographic issues as the same key is being reused.
3) Cross-site scripting (CVE-ID: CVE-2021-32792)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data within the "OIDCPreservePost On". A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Remediation
Install update from vendor's website.