This vulnerability allows Jetty, a Java-based web server and servlet engine, to accept the `+` character preceding the content-length value in an HTTP/1 header field. This behavior is more permissive than allowed by the RFC, and it results in other servers routinely rejecting such requests with 400 responses. While there is no known exploit scenario, it is conceivable that request smuggling could occur if Jetty is used in conjunction with a server that does not close the connection after sending a 400 response.
The vulnerability has been assigned a CVSS score of 5.3, categorizing it as medium severity. This classification indicates a potential risk to organizations that utilize affected versions of Jetty. The vulnerability impacts all versions of Jetty prior to 9.4.52, 10.0.16, 11.0.16, and 12.0.1, which contain the necessary patches. Organizations should prioritize patching these versions to mitigate associated risks.
Organizations should address this vulnerability in their priority patch cycle, as the improper handling of HTTP headers can lead to significant security implications, particularly in environments where Jetty is deployed alongside other web server technologies.
The urgency to remediate this vulnerability is underscored by its potential for request smuggling attacks. Therefore, it is critical to ensure that all affected installations are updated promptly.
Vulnerability Details
The vulnerability is classified under CWE-130 and impacts the following versions of Jetty: versions prior to 9.4.52, 10.0.16, 11.0.16, and 12.0.1. The official description states that Jetty's handling of the `+` character in HTTP headers is more permissive than defined by the RFC, potentially leading to scenarios that can be exploited under specific conditions.
Organizations utilizing Debian Linux versions 10.0, 11.0, and 12.0 may also be affected, as Jetty is commonly used in conjunction with these distributions.
Technical Analysis
The root cause of this vulnerability stems from the handling of HTTP headers, where Jetty does not strictly enforce RFC compliance for the `Content-Length` header. This can lead to situations where malicious requests are misinterpreted, potentially resulting in request smuggling.
The attack vector is network-based, with low attack complexity and no privileges required to exploit this vulnerability. User interaction is not necessary, meaning that an attacker can exploit this flaw without user engagement. The integrity impact is rated as low, while confidentiality and availability impacts are rated as none.
Risk & Impact Analysis
Risk to organizations includes potential request smuggling, which can lead to unauthorized access, data leakage, or other security incidents. The blast radius of this vulnerability could extend to any application or service relying on Jetty for HTTP processing, especially in multi-tier architectures.
Given the CVSS score of 5.3, organizations should address this vulnerability in their priority patch cycle. The risk is amplified if Jetty operates in environments where it interfaces with other web technologies that may not handle the nuances of HTTP headers as permissively.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of Jetty prior to 9.4.52, 10.0.16, 11.0.16, and 12.0.1 are affected. This includes various beta versions of Jetty 12.0.0 and Debian Linux versions 10.0, 11.0, and 12.0.
Mitigation & Remediation
Organizations should promptly update to Jetty versions 9.4.52, 10.0.16, 11.0.16, or 12.0.1 to mitigate this vulnerability. If immediate patching is not feasible, consider implementing network controls to limit exposure to potentially malicious requests and monitor traffic for anomalies.
Additional security measures include configuration hardening and conducting regular security assessments to identify potential vulnerabilities within the environment. Organizations are encouraged to validate remediation effectiveness through penetration testing to ensure that similar weaknesses are addressed.
Detection Guidance
Monitor logs for unusual HTTP request patterns, specifically those that include unexpected characters in header fields. Behavioral anomalies such as unexpected 400 responses from the server should also be noted. Additionally, implement network signatures to detect potential exploitation attempts.
AppSecure Threat Intelligence Insight
This vulnerability represents a broader trend of improper HTTP header handling across various web applications. Security teams should take this opportunity to review their configurations and ensure compliance with RFC standards to prevent similar vulnerabilities in the future.
Organizations should remain vigilant against potential request smuggling attacks that may exploit such vulnerabilities, and develop comprehensive security policies that include regular updates and security training for development teams.
For further insights into application security and best practices, refer to our resource on penetration testing methodology, and explore our vulnerability management program for a structured approach to addressing security weaknesses.
Finally, consider leveraging our API security best practices to enhance your overall security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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