CVE-2011-5058 in CoDeSys
Summary
by MITRE
The CmbWebserver.dll module of the Control service in 3S CoDeSys 3.4 SP4 Patch 2 allows remote attackers to create arbitrary directories under the web root by specifying a non-existent directory using \ (backslash) characters in an HTTP GET request.
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Analysis
by VulDB Data Team • 02/13/2019
The vulnerability identified as CVE-2011-5058 resides within the CmbWebserver.dll module of the Control service in 3S CoDeSys 3.4 SP4 Patch 2, representing a significant security flaw that enables remote attackers to manipulate directory structures on affected systems. This issue manifests through the web server's handling of HTTP GET requests where malicious actors can exploit improper input validation to create arbitrary directories under the web root directory. The vulnerability specifically leverages the use of backslash characters in directory paths, which should normally be rejected or properly sanitized by the web server component. The flaw stems from inadequate path validation and sanitization mechanisms within the web server module, allowing attackers to traverse directory structures and potentially gain unauthorized access to sensitive system resources.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious HTTP GET request containing backslash characters in the directory path parameter. The CmbWebserver.dll module fails to properly validate these path components, enabling the creation of arbitrary directories under the web root. This type of vulnerability falls under CWE-22, which describes Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal. The vulnerability represents a directory traversal attack vector that allows attackers to manipulate the file system by using special characters to navigate beyond the intended directory structure. The web server's failure to sanitize input paths creates a condition where attacker-controlled data can directly influence the directory creation process, potentially leading to unauthorized file system modifications.
The operational impact of this vulnerability extends beyond simple directory creation, as it provides attackers with the capability to establish persistent access points within the web server's directory structure. An attacker could potentially create malicious directories containing web shells or other malicious components, effectively gaining a foothold within the system's web infrastructure. The vulnerability affects the integrity and confidentiality of the web server environment, as unauthorized directory creation could lead to privilege escalation or further exploitation of the system. This flaw particularly impacts industrial control systems that rely on CoDeSys for automation and control, where the web server component may be exposed to external networks, increasing the attack surface and potential impact. The vulnerability's remote exploitability means that attackers do not require local system access, making it particularly dangerous in networked environments where industrial control systems are connected to corporate networks.
Mitigation strategies for CVE-2011-5058 should focus on immediate patching of the 3S CoDeSys software to the latest available version that addresses this specific vulnerability. Organizations should implement network segmentation to isolate industrial control systems from general corporate networks, reducing the attack surface for remote exploitation attempts. Input validation should be strengthened at the web server level to reject or sanitize any path components containing backslash characters or other potentially dangerous path traversal sequences. Network monitoring should be enhanced to detect unusual directory creation patterns or suspicious HTTP GET requests containing malformed path parameters. Security teams should also consider implementing web application firewalls that can detect and block malicious path traversal attempts. The vulnerability demonstrates the importance of proper input sanitization and access control mechanisms in web server components, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1078.004 for valid accounts. Organizations should also conduct comprehensive vulnerability assessments to identify similar path traversal vulnerabilities in other web server components and ensure proper security hardening practices are implemented across all industrial control system environments.