CVE-2023-28709 is a high-severity vulnerability in Apache Tomcat that arises from an incomplete fix for CVE-2023-24998. This vulnerability allows for a potential denial of service if non-default HTTP connector settings are configured such that the maximum parameter count can be reached using query string parameters. Specifically, if an attacker submits a request with exactly the maximum number of parameters allowed, they can bypass the limit on uploaded request parts, resulting in service disruption.
The CVSS score for this vulnerability is 7.5, indicating a high severity level. The attack vector is network-based, requiring no privileges or user interaction, which heightens the risk for organizations running affected versions of Tomcat. The potential impact on availability is particularly concerning, as it could lead to service outages.
Organizations using Apache Tomcat 11.0.0-M2 to 11.0.0-M4, 10.1.5 to 10.1.7, 9.0.71 to 9.0.73, and 8.5.85 to 8.5.87 are at risk. It is crucial for defenders to evaluate their configurations and apply necessary patches or mitigations to address this vulnerability.
Given that this vulnerability has not been associated with any public exploits or proof of concept, organizations should act proactively to secure their systems against potential threats that may arise from its exploitation.
Organizations should prioritize patching immediately.
Vulnerability Details
The fix for CVE-2023-24998 was incomplete for the following versions of Apache Tomcat: 11.0.0-M2 to 11.0.0-M4, 10.1.5 to 10.1.7, 9.0.71 to 9.0.73, and 8.5.85 to 8.5.87. This vulnerability allows attackers to bypass the limit for uploaded request parts if the maxParameterCount is reached with query string parameters, leading to a potential denial of service.
This vulnerability has a CVSS score of 7.5, classified as high severity. It affects the availability of services, as indicated by the high availability impact score. The attack vector is network-based, with low attack complexity and no privileges required.
The vulnerability has been classified under CWE-193, which pertains to the incorrect handling of input parameters.
The vulnerability was published on May 22, 2023, and is currently listed as modified.
Technical Analysis
The root cause of CVE-2023-28709 stems from an incomplete fix related to input parameter handling in Apache Tomcat. When non-default HTTP connector settings are configured, the application may allow an attacker to supply a number of query string parameters that match the maximum allowed, thus bypassing the limits set for uploaded request parts.
The attack vector is network-based, meaning that an attacker can exploit this vulnerability remotely without needing physical access to the server. The attack complexity is considered low, as it does not require advanced skills or knowledge. Additionally, no privileges or user interaction are needed to carry out this attack.
There is an impact on availability, as successful exploitation of this vulnerability can lead to denial of service. However, there are no impacts on confidentiality or integrity, as indicated by the respective scores.
Risk & Impact Analysis
Risk to organizations includes service disruption due to denial of service. If exploited, this vulnerability could allow an attacker to overload the server, preventing legitimate users from accessing the application. Given the broad usage of Apache Tomcat, the potential blast radius of this vulnerability is significant.
Organizations should assess their exposure to this vulnerability in relation to their deployment of affected versions of Apache Tomcat. The urgency for addressing this vulnerability is high, given its potential impact on availability and the ease of exploitation.
Organizations should prioritize patching immediately.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Apache Tomcat include: 11.0.0-M2 to 11.0.0-M4, 10.1.5 to 10.1.7, 9.0.71 to 9.0.73, and 8.5.85 to 8.5.87. Organizations should ensure they are running patched versions to mitigate this risk.
Mitigation & Remediation
Organizations should patch affected versions of Apache Tomcat to resolve this vulnerability. The recommended action is to upgrade to the latest stable release that addresses this issue. If immediate patching is not feasible, organizations should consider implementing configuration hardening and network controls to limit exposure. Regular monitoring for unusual behavior should also be instituted to detect any potential exploitation attempts.
For more information on security testing practices, organizations can refer to the penetration testing services offered by AppSecure.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for indicators of unusual query string parameter usage. Behavioral anomalies, such as unexpected service outages or performance degradation, should also be tracked. Implementing network signatures that identify abnormal traffic patterns can assist in early detection.
AppSecure Threat Intelligence Insight
CVE-2023-28709 highlights ongoing challenges in managing input parameter limits within web applications. As organizations increasingly rely on web technologies, vulnerabilities like this emphasize the need for comprehensive security assessments. Security teams should ensure that all components are regularly reviewed for configuration and vulnerability management.
For further best practices on vulnerability management, organizations can explore our guide on designing a vulnerability management program. Furthermore, understanding the importance of penetration testing methodology can significantly improve risk posture. Lastly, organizations should remain informed on penetration testing report best practices to ensure that vulnerabilities are effectively addressed.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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