CVE-2021-23127 [20210301] - Core - Insecure randomness within 2FA secret generation
Joomla CMS uses insufficient randomness for 2FA secrets, allowing attackers to potentially bypass two-factor authentication.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-23127?
CVE-2021-23127 is a critical vulnerability in Joomla Joomla\!, published on 4 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue was discovered in Joomla! 3.2.0 through 3.9.24. Usage of an insufficient length for the 2FA secret accoring to RFC 4226 of 10 bytes vs 20 bytes.
Which versions are affected by CVE-2021-23127?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 3.2.0 | 3.9.25 |
Products include Joomla Joomla\!.
How do I fix CVE-2021-23127?
Upgrade joomla to 3.9.25 or later.
Is CVE-2021-23127 being exploited?
There is no known exploitation of CVE-2021-23127 in the wild and no public exploit code.
Other vulnerabilities in Joomla Joomla\!
- CVE-2016-10033 PHPMailer Command Injection
- CVE-2023-23752 Joomla! Improper Access Control
- CVE-2026-48902 Joomla! Core - [20260518] - Transport encryption downgrade for password and username reset links
- CVE-2025-25226 [20250401] - Joomla Framework - SQL injection vulnerability in quoteNameStr method of Database package
- CVE-2022-23795 [20220303] - Core - User row are not bound to a authentication mechanism
Sources
Also known as BIT-joomla-2021-23127, GHSA-8rrc-xf7x-g3cf.