Listen to this Post
Apache Tomcat, a popular open-source web server, has been found to have a significant vulnerability that could potentially expose security-sensitive files, execute remote code, or allow malicious content to be injected into uploaded files. This issue, which affects several versions of Apache Tomcat, can be triggered under specific conditions, posing a serious risk to web applications running on these affected versions. This article delves into the specifics of the vulnerability, the conditions under which it occurs, and recommended actions to mitigate the threat.
Vulnerability Overview
The reported vulnerability arises from a flaw in Apache Tomcat’s default servlet configuration, where “path equivalence” issues allow an attacker to manipulate file names. Specifically, the use of an internal dot (.) in file names can lead to remote code execution (RCE), information disclosure, or the injection of malicious content into uploaded files. This issue affects Apache Tomcat versions 11.0.0-M1 through 11.0.2, 10.1.0-M1 through 10.1.34, and 9.0.0.M1 through 9.0.98.
The conditions that enable this vulnerability are:
- Write permissions are enabled for the default servlet (which is not the default setting but can be configured).
- Partial PUT support is enabled (enabled by default).
- The target URL for uploading security-sensitive files is a sub-directory of a public upload location.
- The attacker knows the names of the sensitive files being uploaded.
- The files are uploaded using partial PUT requests.
In the event that these conditions are met, the attacker may be able to either access sensitive files, inject malicious content into those files, or in some cases, execute remote code on the server.
Specific Remote Code Execution Conditions
The vulnerability can be further exploited to achieve remote code execution (RCE) under additional circumstances:
- Write permissions are enabled for the default servlet.
– Partial PUT support is enabled.
– The web application uses
- The application includes a vulnerable library that could facilitate a deserialization attack.
If an attacker successfully exploits these conditions, they could execute arbitrary code on the server, leading to a complete compromise of the application.
Recommendations for Mitigation
Users running affected versions of Apache Tomcat should immediately upgrade to the following patched versions to address this vulnerability:
– Apache Tomcat 11.0.3 or higher
– Apache Tomcat 10.1.35 or higher
– Apache Tomcat 9.0.99 or higher
These updates address the vulnerability by fixing the issues in the default servlet configuration, improving security measures, and preventing the exploitation of this flaw.
Credits and References
This vulnerability was discovered by COSCO Shipping Lines DIC Finder and sw0rd1ight (GitHub: https://github.com/sw0rd1ight). For more details, you can refer to the vendor advisory provided here: Apache Tomcat Security Advisory.
What Undercode Says:
The discovered flaw in Apache Tomcat highlights a critical issue that could be easily exploited by attackers with basic knowledge of the affected web server’s configuration. Path equivalence problems involving file names and the configuration of default servlets open the door to severe consequences, such as unauthorized access to sensitive files, the injection of malicious content, or remote code execution.
While Tomcat is a widely used platform, this vulnerability emphasizes the importance of security best practices, particularly when configuring servers for file uploads. It’s worth noting that many of the conditions that lead to this vulnerability—such as enabling write permissions for the default servlet or supporting partial PUT requests—are not enabled by default. However, this doesn’t diminish the risk if those settings have been configured improperly or forgotten.
One of the most concerning aspects of this vulnerability is its potential to escalate to remote code execution, which could allow attackers to fully compromise web applications running on affected versions. As with many security vulnerabilities, timely patching is key. The release of newer, patched versions of Tomcat demonstrates the importance of staying current with software updates to avoid such security threats.
Apache Tomcat’s design, which often includes file-based session persistence, is another vector that attackers may exploit. This ties into broader concerns regarding server configurations that allow applications to store session data in a file system. If misconfigured, this can lead to exploitation of Tomcat’s default settings or even introduce vulnerable third-party libraries that allow deserialization attacks.
The vulnerability is a clear reminder of the need for robust security testing and configuration management when working with web servers and applications. In particular, administrators should be vigilant about the security settings that enable or disable certain features like partial PUT and servlet write permissions. In doing so, they can significantly reduce the likelihood of falling victim to such attacks.
The bottom line is that, while this vulnerability can be complex to exploit, it’s also avoidable with proper security configurations and regular updates. Apache Tomcat users must prioritize patching to stay secure.
Fact Checker Results:
- Severity of the Vulnerability: The vulnerability poses a significant risk but can be mitigated by adhering to best security practices and upgrading to the latest patched versions of Apache Tomcat.
- Exploitability: While not enabled by default, the conditions necessary to exploit the flaw can be easily configured by misinformed or negligent administrators, making it a serious concern.
- Resolution: Apache has addressed the issue with updated versions, making patching the primary mitigation strategy.
References:
Reported By: https://www.cve.org/CVERecord?id=CVE-2025-24813
Extra Source Hub:
https://www.github.com
Wikipedia
Undercode AI
Image Source:
Pexels
Undercode AI DI v2
