CVE-2001-1118 in Webserver
Summary
by MITRE
A module in Roxen 2.0 before 2.0.92, and 2.1 before 2.1.264, does not properly decode UTF-8, Mac and ISO-2202 encoded URLs, which could allow a remote attacker to execute arbitrary commands or view arbitrary files via an encoded URL.
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Analysis
by VulDB Data Team • 09/29/2025
The vulnerability identified as CVE-2001-1118 affects the Roxen web server software, specifically versions prior to 2.0.92 and 2.1.264, representing a critical security flaw in URL handling mechanisms. This issue stems from inadequate decoding of various character encoding schemes including UTF-8, Mac encoding, and ISO-2202 formats within the server's module architecture. The flaw exists in the way the software processes incoming URLs that contain encoded characters, creating a path for malicious exploitation through carefully crafted encoded requests that bypass normal security controls.
The technical implementation of this vulnerability resides in the improper handling of multibyte character sequences during URL parsing operations. When the Roxen server receives a request containing encoded URLs, it fails to properly normalize or decode these sequences before processing them, leading to a situation where encoded characters can be interpreted as literal path components or command arguments. This misinterpretation occurs because the software does not fully account for the different encoding standards and their potential overlap or ambiguity during the decoding phase, creating a condition where maliciously encoded input can be transformed into unexpected execution paths.
The operational impact of this vulnerability extends to both remote code execution and unauthorized file access capabilities, making it particularly dangerous for web server environments. An attacker could exploit this flaw by crafting specially encoded URLs that, when processed by the vulnerable Roxen server, would result in arbitrary command execution on the target system or allow access to files that should otherwise be protected. The vulnerability essentially creates a bypass mechanism for normal access controls and input validation, enabling attackers to manipulate the server's behavior through character encoding manipulation rather than traditional injection techniques.
This vulnerability maps directly to CWE-174, which describes the weakness of insufficient encoding or normalization of input data, and aligns with ATT&CK technique T1059 for command and script injection. The attack surface is particularly concerning as it operates at the protocol level, where the encoding normalization failure creates a persistent vector for exploitation across different operating systems and network environments. The vulnerability demonstrates a fundamental flaw in input sanitization processes where the server assumes that properly encoded input will behave predictably, failing to account for the complex interactions between different encoding standards.
Mitigation strategies for this vulnerability require immediate patching of the Roxen server software to versions 2.0.92 or 2.1.264 and later, which contain the necessary fixes for proper URL decoding mechanisms. Organizations should also implement additional network-level protections such as web application firewalls that can detect and block suspicious encoded URL patterns, though this represents a secondary defense measure. System administrators should conduct thorough vulnerability assessments to ensure that all Roxen installations are updated and monitor for any attempts to exploit this specific encoding-based attack vector. The fix implemented in the patched versions addresses the core issue by ensuring proper normalization of character encodings before any processing occurs, preventing the exploitation path that allowed attackers to manipulate the server's interpretation of encoded input.