Authentication bypass in Apache Tomcat JNDI Realm

Published: 2021-07-29
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-30640
Exploitation vector Network
Public exploit N/A
Vulnerable software
Apache Tomcat
Server applications / Web servers

Vendor Apache Foundation

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Improper Authentication

EUVDB-ID: #VU55417

Risk: Medium


CVE-ID: CVE-2021-30640

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No


The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in the JNDI Realm when processing authentication requests. A remote attacker can authenticate using variations of a valid user name and bypass some of the protection provided by the LockOut Realm.


Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 10.0.0 - 10.0.5, 9.0.0 - 9.0.45, 8.5.0 - 8.5.65, 7.0.0 - 7.0.108

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

How the attacker can exploit this vulnerability?

Is there known malware, which exploits this vulnerability?