CVE-2024-9823 in Jetty
Summary
by MITRE • 10/14/2024
Description There exists a security vulnerability in Jetty's DosFilter which can be exploited by unauthorized
users to cause remote denial-of-service (DoS) attack on the server using DosFilter. By repeatedly sending crafted requests,
attackers can trigger OutofMemory errors and exhaust the server's memory finally.
Vulnerability details The Jetty DoSFilter (Denial of Service Filter) is a security filter designed to protect web
applications against certain types of Denial of Service (DoS) attacks and other abusive behavior. It
helps to mitigate excessive resource consumption by limiting the rate at which clients can make
requests to the server. The DoSFilter monitors and tracks client request patterns, including
request rates, and can take actions such as blocking or delaying requests from clients that exceed
predefined thresholds. The internal tracking of requests in DoSFilter is the source of this OutOfMemory
condition.
Impact Users of the DoSFilter may be subject to DoS attacks that will ultimately exhaust the memory of the server if they have not configured session passivation or an aggressive session inactivation timeout.
Patches The DoSFilter has been patched in all active releases to no longer support the session tracking mode, even if configured.
Patched releases:
* 9.4.54
* 10.0.18
* 11.0.18
* 12.0.3
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability identified as CVE-2024-9823 affects Jetty's DosFilter component, which is designed to protect web applications against denial-of-service attacks by monitoring and limiting client request patterns. This security flaw represents a critical weakness in the filter's internal memory management system that can be exploited by unauthorized users to trigger remote denial-of-service conditions. The vulnerability specifically manifests when attackers repeatedly send crafted requests to the server, causing the DoSFilter to consume excessive memory resources until the system experiences OutOfMemory errors and ultimately becomes unresponsive.
The technical root cause of this vulnerability lies within the DosFilter's internal tracking mechanisms that monitor client request patterns and maintain state information about client behavior. When the filter operates in session tracking mode, it maintains detailed records of client activities in memory, creating a memory leak condition that accumulates over time. This flaw is categorized under CWE-400 as an excessive resource consumption vulnerability, where the application fails to properly manage memory allocation during normal operational conditions. The vulnerability is particularly dangerous because it allows attackers to consume server resources without requiring authentication or elevated privileges, making it an attractive target for malicious actors seeking to disrupt service availability.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire server operations. When exploited successfully, the vulnerability can exhaust server memory resources completely, leading to application crashes and complete service unavailability. Systems that rely on Jetty's DosFilter for protection may become vulnerable to coordinated attack campaigns that systematically consume memory resources, ultimately causing cascading failures throughout the affected infrastructure. The vulnerability is particularly concerning in environments where session passivation has not been configured or where aggressive session inactivation timeouts have not been implemented, as these configurations provide crucial protection against memory exhaustion scenarios.
Organizations using affected versions of Jetty should immediately implement mitigation strategies to address this vulnerability. The most effective approach involves upgrading to patched releases that eliminate support for the problematic session tracking mode within the DosFilter. The patched versions include releases 9.4.54, 10.0.18, 11.0.18, and 12.0.3, which have been specifically designed to prevent the memory exhaustion conditions that previously occurred. Security teams should also consider implementing additional monitoring and alerting mechanisms to detect unusual memory consumption patterns that might indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 (Endpoint Denial of Service) and represents a significant threat to system availability that requires immediate remediation to maintain operational continuity and protect against potential business disruption.