CVE-2003-0833 in webfs
Summary
by MITRE
Stack-based buffer overflow in webfs before 1.20 allows attackers to execute arbitrary code by creating directories that result in a long pathname.
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Analysis
by VulDB Data Team • 07/20/2025
The vulnerability identified as CVE-2003-0833 represents a critical stack-based buffer overflow in the webfs web server software prior to version 1.20. This flaw resides in the directory creation handling mechanism where the software fails to properly validate the length of pathname arguments when processing directory creation requests. The vulnerability stems from inadequate input sanitization and bounds checking within the webfs implementation, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code on affected systems.
The technical implementation of this vulnerability occurs when an attacker crafts malicious directory names that exceed the allocated buffer space on the stack. The webfs server processes these directory paths without sufficient length validation, allowing a buffer overflow condition to occur when the system attempts to store the excessively long pathname in memory. This stack corruption can overwrite adjacent memory locations including return addresses, function pointers, and other critical execution data structures. The vulnerability is particularly dangerous because it allows remote code execution without requiring authentication, making it a severe threat to web server security. The flaw maps directly to CWE-121 Stack-based Buffer Overflow, which is categorized under the broader weakness class of buffer overflows that occur when data is written beyond the bounds of a fixed-length buffer allocated on the stack.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with complete control over the affected web server. Successful exploitation can lead to unauthorized access to the server's file system, allowing attackers to read sensitive data, modify web content, install backdoors, or use the compromised server as a launching point for further attacks within the network. The vulnerability affects systems running webfs versions before 1.20, which were commonly deployed in various server environments including those hosting public websites, internal web applications, and file sharing services. This makes the impact particularly widespread given the popularity of webfs as a lightweight web server solution for Unix-like operating systems. The vulnerability can be exploited through simple HTTP requests that create directory structures with maliciously long pathnames, making it accessible to attackers with minimal technical expertise.
Mitigation strategies for CVE-2003-0833 primarily focus on immediate software updates and system hardening measures. The most effective solution is upgrading to webfs version 1.20 or later, which includes proper bounds checking and input validation for pathname handling. Organizations should also implement network-level protections such as firewall rules that restrict access to web server functionality and monitor for suspicious directory creation patterns. Input validation should be enhanced at the application level by implementing strict pathname length limits and sanitizing all user-supplied directory names before processing. Additionally, system administrators should consider implementing address space layout randomization and stack canaries to make exploitation more difficult. From an ATT&CK perspective, this vulnerability aligns with techniques such as T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter, as attackers can leverage the buffer overflow to execute arbitrary commands and establish persistent access to compromised systems. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other web server implementations.