CVE-2011-1184: Authentication Bypass in Apache Tomcat
Summary
CVE-2011-1184: Authentication Bypass in Apache Tomcat. Affects org.apache.tomcat:tomcat across 3 version ranges.
>= 5.5.0, < 5.5.34
>= 6.0.0, < 6.0.33
>= 7.0.0, < 7.0.12
Fixed in 5.5.34, 6.0.33 or 7.0.12, depending on the release line you run. How to fix ↓
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Background
Apache Tomcat is an open-source web server and servlet container that is widely used for hosting Java-based web applications. It provides a robust and scalable platform for running Java web applications and supports various protocols, including HTTP. The HTTP Digest Access Authentication is a security mechanism implemented in Apache Tomcat to protect against unauthorized access. However, versions 5.5.x before 5.5.34, 6.x before 6.0.33, and 7.x before 7.0.12 of Apache Tomcat are vulnerable to an authentication bypass issue.
Vulnerability Detail
The vulnerability in Apache Tomcat allows remote attackers to bypass intended access restrictions by sniffing the network for valid requests. This is due to the lack of countermeasures against replay attacks in the HTTP Digest Access Authentication implementation. The attacker can intercept valid requests and extract the nonce (server nonce) and nonce-count (client nonce count) values, which are not properly checked. By replaying these values, the attacker can bypass the authentication mechanism and gain unauthorized access to the system. This vulnerability poses a moderate risk as it can lead to unauthorized access and potential data breaches.
How To Fix
Latest published version: 11.0.27 as of 23 Oct 2026
Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
>= 5.5.0, < 5.5.345.5.34 -
>= 6.0.0, < 6.0.336.0.33 -
>= 7.0.0, < 7.0.127.0.12
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
There is no known workaround for this vulnerability. It is recommended to upgrade to the fixed versions of Apache Tomcat as mentioned above.
Conclusion
The authentication bypass vulnerability in Apache Tomcat can lead to unauthorized access and potential data breaches. It is crucial to upgrade to the fixed versions of Apache Tomcat to mitigate this vulnerability. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for org.apache.tomcat:tomcat →
FAQ
Apache Tomcat is an open-source web server and servlet container that is widely used for hosting Java-based web applications.
HTTP Digest Access Authentication is a security mechanism used to protect against unauthorized access by requiring clients to provide a valid username and password.
The vulnerability occurs due to the lack of countermeasures against replay attacks in the HTTP Digest Access Authentication implementation.
The vulnerability allows remote attackers to bypass intended access restrictions and gain unauthorized access to the system.
To fix this vulnerability, it is recommended to upgrade to a fixed version of Apache Tomcat.
References
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