CVE-2024-21733 Scanner

Apache Tomcat is a widely used open-source implementation of the Java Servlet, JavaServer Pages, and WebSocket technologies. It is deployed by enterprises around the globe for its robust, flexible, and efficient web server functionalities, primarily serving Java-based web applications. Organizations across various sectors, including finance, health, and technology, leverage Apache Tomcat for its reliability and extensive ecosystem support. The platform provides a cost-effective solution for demanding web application environments and is supported by a knowledgeable community, making it a popular choice for many developers. Enterprise-grade systems rely on Apache Tomcat to handle intensive workloads efficiently, ensuring a seamless user experience. As the backbone of many web infrastructures, its performance and security are crucial for the functioning of reliant applications.

HTTP Request Smuggling is a critical vulnerability where an attacker crafts an HTTP request to manipulate the way a web server processes subsequent requests. This vulnerability often arises due to incorrect handling or interpretations of HTTP request headers, particularly concerning content length. When exploited, it can lead to a variety of impacts such as data leakage, cross-user attacks, and cache poisoning. In the case of Apache Tomcat, the vulnerability allows for client-side de-sync attacks, where a malicious payload causes the client and server communications to desynchronize. By exploiting the Apache Tomcat's failure to handle the content-length of POST requests properly, attackers can intercept or modify exchanged information. This vulnerability poses a significant risk due to its potential to lead to unauthorized data access or manipulation.

The technical aspect of this vulnerability centers around how Apache Tomcat improperly processes HTTP request headers, notably the Content-Length header used in POST requests. The vulnerable endpoints exist in specific versions, from 8.5.7 through 8.5.63 and 9.0.0-M11 through 9.0.43. Attackers can exploit these endpoints by crafting requests that take advantage of the server's inability to correctly process content-length, resulting in request de-synchronization. This may lead to malicious actions being executed on the client-server communication channel, including unauthorized data access. The vulnerability is detected by sending crafted requests and analyzing server responses for bypass behaviors. The incorrect handling in Apache Tomcat allows this exploitation path, making the systems susceptible to further, possibly severe, exploitations.

Exploiting this vulnerability can have dire effects, including carrying out a range of attacks such as unauthorized information disclosure, cross-user data breaches, and even hijacking of active sessions. It allows attackers to manipulate server-client communications, resulting in data leaks or illegitimate actions being performed in user accounts. While giving attackers the ability to smuggle information, this vulnerability undermines the integrity and confidentiality of server-client transactions, leading to potentially significant data breaches. Furthermore, it poses risks to the internal systems if attackers exploit the vulnerability to launch broader attacks within an organization's network. Organizations could face compliance violations, reputational damage, and financial losses due to the exploit of this vulnerability.

REFERENCES

• https://lists.apache.org/thread/h9bjqdd0odj6lhs2o96qgowcc6hb0cfz
• https://sn1persecurity.com/wordpress/cve-2024-21733-apache-tomcat-http-request-smuggling/