CVE-2006-1159 in Efs Web Server
Summary
by MITRE
Format string vulnerability in Easy File Sharing (EFS) Web Server 3.2 allows remote attackers to cause a denial of service (server crash) and possibly execute arbitrary code via format string specifiers in the query string argument in an HTTP GET request.
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Analysis
by VulDB Data Team • 06/15/2019
The vulnerability identified as CVE-2006-1159 represents a critical format string flaw within the Easy File Sharing Web Server version 3.2, specifically affecting the server's handling of HTTP GET requests containing malformed query string arguments. This issue stems from the server's insecure implementation of string formatting functions that fail to properly validate input data before processing. The vulnerability manifests when the web server receives an HTTP GET request with a specially crafted query string containing format specifiers such as %s, %d, or %x, which are typically used to control output formatting in C programming languages. When these unvalidated format specifiers are passed directly to functions like printf or sprintf without proper sanitization, the server's memory management becomes compromised, creating opportunities for both denial of service and potential code execution attacks.
The technical exploitation of this vulnerability occurs through the manipulation of the HTTP query string parameter, where attackers can inject format specifiers that cause the server's string formatting routines to read arbitrary memory locations or write data to unintended memory addresses. This flaw directly maps to CWE-134, which specifically addresses the use of format strings with user-supplied data without proper validation or sanitization. The server's failure to implement proper input validation and sanitization mechanisms creates a pathway for attackers to leverage the format string vulnerability to either cause the web server process to crash through memory corruption or potentially execute arbitrary code by overwriting critical program memory locations. The vulnerability's impact extends beyond simple service disruption as it can enable attackers to gain unauthorized access to the server's operating system environment.
From an operational standpoint, this vulnerability poses significant risks to organizations relying on Easy File Sharing Web Server 3.2 for file sharing and web serving functions. The remote exploit capability means that attackers can target the vulnerable server from anywhere on the internet without requiring local access or authentication credentials. The potential for arbitrary code execution creates opportunities for attackers to establish persistent backdoors, escalate privileges, or use the compromised server as a launching point for attacks against other systems within the network infrastructure. The denial of service component alone can disrupt critical business operations by making file sharing services unavailable to legitimate users, while the code execution capability can lead to complete system compromise. This vulnerability aligns with several ATT&CK techniques including T1059 for command and scripting interpreter and T1499 for network denial of service, representing both immediate availability impacts and longer-term persistence threats.
Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided patches or upgrading to newer versions of the Easy File Sharing Web Server that address the format string vulnerability. Network-level protections such as web application firewalls can provide additional defense-in-depth by filtering out suspicious query string patterns containing format specifiers. System administrators should also consider implementing input validation rules that prevent the processing of query strings containing potentially dangerous formatting characters. The vulnerability demonstrates the critical importance of secure coding practices, particularly around input validation and string handling in web applications, and serves as a reminder of the necessity for regular security assessments and vulnerability management processes. Organizations should also review their incident response procedures to ensure readiness for potential exploitation of similar vulnerabilities in their web infrastructure components.