CVE-2006-5850 in Essentia Web Server
Summary
by MITRE
Stack-based buffer overflow in Essentia Web Server 2.15 for Windows allows remote attackers to execute arbitrary code via a long URI, as demonstrated by a GET or HEAD request. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 04/27/2026
The CVE-2006-5850 vulnerability represents a critical stack-based buffer overflow flaw in the Essentia Web Server version 2.15 running on Windows platforms. This vulnerability resides in the server's handling of Uniform Resource Identifiers within HTTP requests, specifically affecting GET and HEAD request methods. The flaw arises when the web server processes excessively long URIs without proper bounds checking, leading to memory corruption that can be exploited by remote attackers to execute arbitrary code on the affected system.
The technical implementation of this vulnerability demonstrates a classic stack overflow condition where input data exceeds the allocated buffer space, causing adjacent memory locations to be overwritten. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is categorized as a fundamental memory safety issue in software development. When an attacker crafts a malicious HTTP request containing an overly long URI, the server's parsing routine fails to validate the input length, allowing the overflow to occur during the processing of the request. The overflow corrupts the stack memory, potentially enabling attackers to overwrite return addresses and function pointers, thereby gaining control over the program execution flow.
From an operational perspective, this vulnerability presents a severe threat to web server security as it allows remote code execution without requiring authentication or prior access to the system. The attack surface is broad since any HTTP client can potentially exploit this flaw by simply sending a malformed request to the vulnerable server. The impact extends beyond simple code execution to potentially enable full system compromise, privilege escalation, and data exfiltration. Security analysts should note that this vulnerability aligns with ATT&CK technique T1190 - Exploit Public-Facing Application, which describes how adversaries target vulnerabilities in externally accessible applications to gain initial access to target systems.
The exploitation of this vulnerability typically involves crafting a specially designed URI that exceeds the buffer capacity, often through the use of repeated characters or encoded sequences that, when processed by the server, trigger the overflow condition. The affected Essentia Web Server 2.15 version represents a specific software implementation that lacks proper input validation mechanisms, making it susceptible to this type of attack. Organizations running this version of the web server should immediately implement mitigations including software updates, input validation patches, and network segmentation measures to prevent exploitation attempts. The vulnerability highlights the critical importance of proper memory management and input validation in web server implementations, particularly in environments where external access is permitted. Additionally, this issue underscores the need for regular security assessments and vulnerability management processes to identify and remediate similar flaws in legacy software systems.