CVE-2010-3198 in Zope
Summary
by MITRE
ZServer in Zope 2.10.x before 2.10.12 and 2.11.x before 2.11.7 allows remote attackers to cause a denial of service (crash of worker threads) via vectors that trigger uncaught exceptions.
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Analysis
by VulDB Data Team • 01/21/2025
The vulnerability identified as CVE-2010-3198 represents a critical denial of service weakness within the ZServer component of Zope application server versions 2.10.x prior to 2.10.12 and 2.11.x prior to 2.11.7. This flaw specifically targets the server's handling of exceptional conditions, creating a scenario where remote attackers can deliberately trigger worker thread crashes through unhandled exception scenarios. The ZServer serves as the core HTTP server component within Zope, responsible for processing incoming web requests and managing worker processes that handle concurrent client connections. When these worker threads encounter uncaught exceptions during request processing, they terminate abruptly, leading to service disruption and potential system instability.
The technical mechanism behind this vulnerability involves the improper exception handling within ZServer's request processing pipeline. When certain malformed or specially crafted requests are submitted to the server, they can cause internal exceptions that are not properly caught and managed by the application's error handling routines. These uncaught exceptions propagate through the execution stack and result in the immediate termination of worker threads responsible for processing those requests. The flaw operates at the application level rather than at the system or network level, making it particularly insidious as it can be exploited through normal HTTP traffic without requiring special privileges or access to system resources.
From an operational impact perspective, this vulnerability creates significant disruption to services running on affected Zope installations. The denial of service occurs at the worker thread level, meaning that individual worker processes crash and must be restarted, which can lead to temporary unavailability of the web application. In high-traffic environments, multiple concurrent attacks can overwhelm the system by causing numerous worker threads to crash simultaneously, potentially leading to complete service degradation. The impact extends beyond simple availability issues as the crashing threads can consume system resources and potentially lead to resource exhaustion, making the system increasingly unstable over time. This vulnerability directly maps to CWE-409, which describes improper handling of exceptional conditions, and aligns with ATT&CK technique T1499.004 for network denial of service attacks.
The recommended mitigation strategies for this vulnerability include immediate patching of affected Zope installations to versions 2.10.12 or 2.11.7, which contain the necessary exception handling improvements. Organizations should also implement robust monitoring and alerting mechanisms to detect unusual patterns of worker thread crashes, which could indicate exploitation attempts. Network-level protections such as rate limiting and request filtering can help reduce the impact of potential attacks by limiting the number of requests that can be processed in a given time period. Additionally, implementing proper application-level error handling and logging can help administrators detect and respond to exploitation attempts more effectively. Security teams should also consider implementing intrusion detection systems that can identify patterns associated with this specific vulnerability, allowing for proactive defense measures against potential exploitation attempts.