CVE-2021-32791 Explained : Impact and Mitigation
Discover the impact of CVE-2021-32791, a vulnerability in mod_auth_openidc prior to version 2.4.9, utilizing a static IV and AAD in AES GCM encryption, leading to known cryptographic weaknesses.
A hardcoded static IV and AAD with a reused key in AES GCM encryption vulnerability was discovered in mod_auth_openidc, an authentication/authorization module for Apache, prior to version 2.4.9. This issue can lead to known cryptographic weaknesses due to the reuse of the same key.
Understanding CVE-2021-32791
This section will delve into the details of CVE-2021-32791.
What is CVE-2021-32791?
CVE-2021-32791 involves a vulnerability in mod_auth_openidc, which uses a static IV and AAD in AES GCM encryption, resulting in potential security risks.
The Impact of CVE-2021-32791
The use of static IV and AAD with a reused key in AES GCM encryption poses confidentiality risks due to known cryptographic weaknesses, affecting systems using mod_auth_openidc versions earlier than 2.4.9.
Technical Details of CVE-2021-32791
This section will provide technical insights into CVE-2021-32791.
Vulnerability Description
The vulnerability arises from mod_auth_openidc's utilization of a static IV and AAD in AES GCM encryption, leading to predictable cryptographic nonce generation.
Affected Systems and Versions
The vulnerability impacts systems using mod_auth_openidc versions prior to 2.4.9, specifically affecting zmartzone's mod_auth_openidc implementation.
Exploitation Mechanism
Exploiting this vulnerability requires knowledge of the static IV and AAD values used in AES GCM encryption, potentially enabling unauthorized access or data manipulation.
Mitigation and Prevention
Here, we discuss ways to mitigate and prevent the CVE-2021-32791 vulnerability.
Immediate Steps to Take
Users are advised to update mod_auth_openidc to version 2.4.9 or later to address the vulnerability and enhance cryptographic security.
Long-Term Security Practices
Implementing secure cryptographic practices, such as using dynamic values in encryption operations, can help mitigate risks associated with nonce reuse.
Patching and Updates
Regularly check for security advisories and updates from zmartzone and other relevant sources to stay informed about the latest patches and security enhancements.