CVE-2005-1365 in Pico Server
Summary
by MITRE
Pico Server (pServ) 3.2 and earlier allows remote attackers to execute arbitrary commands via a URL with multiple leading "/" (slash) characters and ".." sequences.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability described in CVE-2005-1365 affects Pico Server version 3.2 and earlier, representing a classic path traversal attack that exploits improper input validation in web server implementations. This issue specifically manifests when processing URLs containing multiple leading forward slash characters followed by directory traversal sequences, creating a condition where malicious users can manipulate the server's file system access patterns. The flaw resides in the server's handling of URL normalization and path resolution mechanisms, where consecutive forward slashes and dot-dot sequences are not properly sanitized or resolved before file access operations are performed. This vulnerability falls under the broader category of directory traversal attacks that have been consistently identified in web server implementations over many years.
The technical implementation of this vulnerability stems from the server's failure to properly canonicalize file paths when processing incoming HTTP requests. When a malicious URL contains multiple leading slashes followed by ".." sequences, the server's internal path resolution logic does not adequately normalize these sequences, allowing attackers to bypass intended directory restrictions. This misconfiguration enables the server to interpret the crafted URL as accessing files outside the intended web root directory, potentially leading to unauthorized access to sensitive system files, configuration data, or other restricted resources. The vulnerability is particularly dangerous because it leverages the fundamental nature of how file systems handle path navigation, making it a persistent threat across different operating systems and server implementations. The flaw aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, and represents a common pattern in web server security issues that have been documented since the early days of internet infrastructure.
The operational impact of this vulnerability extends far beyond simple unauthorized file access, as it can enable attackers to execute arbitrary commands on the underlying system. Once an attacker successfully exploits the path traversal mechanism, they can potentially read system configuration files, access database files, retrieve user credentials, or even upload and execute malicious code. The implications are severe because web servers typically run with elevated privileges, and successful exploitation can lead to complete system compromise. Attackers can leverage this vulnerability to perform reconnaissance activities, escalate privileges, or establish persistent access to the compromised system. The vulnerability's remote nature means that attackers do not require physical access to the server and can exploit it from anywhere on the internet, making it particularly attractive for automated attacks. This type of vulnerability also aligns with ATT&CK technique T1059, which covers command and script injection, as the ability to execute arbitrary commands through path traversal attacks provides attackers with direct system control capabilities.
Mitigation strategies for this vulnerability must address both the immediate security gap and implement broader defensive measures. The most effective immediate solution involves updating to Pico Server version 3.2 or later, where the path traversal vulnerability has been patched. Organizations should also implement URL normalization and validation mechanisms at the server level, ensuring that all incoming requests undergo proper canonicalization before any file system operations are performed. Input validation should be enforced to reject or sanitize any URL containing multiple consecutive forward slashes or directory traversal sequences. Network-level protections such as web application firewalls can provide additional layers of defense by monitoring for suspicious URL patterns and blocking malicious requests before they reach the vulnerable server. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other web server implementations. The remediation process should also include implementing proper access controls and privilege separation, ensuring that web server processes run with minimal required permissions to reduce the potential impact of successful exploitation attempts. Organizations should also consider implementing automated monitoring systems that can detect anomalous file access patterns that might indicate exploitation attempts against similar vulnerabilities.