CVE-2003-0169 in Instant Toptools
Summary
by MITRE
hpnst.exe in the GoAhead-Webs webserver for HP Instant TopTools before 5.55 allows remote attackers to cause a denial of service (CPU consumption) via a request to hpnst.exe that calls itself, which causes an infinite loop.
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Analysis
by VulDB Data Team • 01/28/2025
The vulnerability described in CVE-2003-0169 represents a critical denial of service flaw within the GoAhead-Webs webserver component of HP Instant TopTools versions prior to 5.55. This issue specifically targets the hpnst.exe executable which serves as a key component in the webserver functionality. The vulnerability stems from a design flaw that allows remote attackers to exploit a recursive calling mechanism within the application, creating an infinite loop that consumes excessive cpu resources and ultimately leads to system unresponsiveness. The flaw operates at the application layer of the network stack, making it particularly dangerous as it can be triggered remotely without requiring authentication or specialized privileges. This type of vulnerability falls under the category of resource exhaustion attacks where malicious actors can systematically consume system resources to render services unavailable to legitimate users.
The technical implementation of this vulnerability involves the hpnst.exe process executing a self-referential request that creates an infinite recursive loop. When a malicious request is sent to the webserver targeting hpnst.exe, the application fails to properly validate or terminate the recursive call sequence. This behavior directly maps to CWE-835, which describes the weakness of an infinite loop or recursion without proper termination conditions. The recursive nature of the flaw means that each iteration consumes additional cpu cycles and memory resources, creating a progressive degradation of system performance that eventually leads to complete service denial. The vulnerability demonstrates poor input validation and control flow management within the webserver implementation, allowing attackers to manipulate the execution path through carefully crafted requests.
From an operational perspective, this vulnerability poses significant risks to organizations relying on HP Instant TopTools for their web-based applications. The remote exploit capability means that attackers can trigger the denial of service condition from anywhere on the network, making it particularly dangerous for publicly accessible web servers. The infinite loop consumes cpu resources at an accelerating rate, potentially causing system crashes or rendering the entire webserver unavailable to legitimate users. This vulnerability can be exploited as part of larger attack campaigns where attackers seek to disrupt services or create distractions while conducting other malicious activities. The impact extends beyond simple service disruption as it can affect business continuity and potentially provide attackers with opportunities to escalate their attacks or conduct further reconnaissance on the compromised systems. Organizations may find their web applications becoming unresponsive during peak usage periods, leading to significant operational disruptions and potential financial losses.
The recommended mitigations for this vulnerability include immediate upgrading to HP Instant TopTools version 5.55 or later, which contains the necessary patches to address the recursive calling flaw. System administrators should also implement network-level controls such as rate limiting and access control lists to restrict access to the vulnerable hpnst.exe endpoint. Additionally, monitoring systems should be configured to detect unusual cpu consumption patterns that may indicate exploitation attempts. The vulnerability aligns with several tactics described in the MITRE ATT&CK framework under the service disruption category, specifically targeting the availability aspect of the CIA triad. Organizations should also consider implementing intrusion detection systems that can identify and alert on suspicious recursive request patterns. Regular security assessments and vulnerability scanning should be conducted to identify similar flaws in other web applications and ensure comprehensive protection against similar denial of service attacks.