CVE-2004-1255 in 2fax
Summary
by MITRE
Buffer overflow in the expandtabs function in 2fax 3.04 allows remote attackers to execute arbitrary code via a text file that is converted to TIFF.
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Analysis
by VulDB Data Team • 06/30/2018
The vulnerability described in CVE-2004-1255 represents a critical buffer overflow flaw within the expandtabs function of 2fax version 3.04, a fax conversion utility that processes text files and converts them to TIFF format for fax transmission. This vulnerability resides in the handling of text file inputs during the conversion process, where the application fails to properly validate the length of input data before copying it into fixed-size buffers. The flaw specifically affects the expandtabs function which is responsible for processing tab characters in text files, making it a prime target for exploitation during the fax conversion workflow. The vulnerability is classified as a classic stack-based buffer overflow under CWE-121, where insufficient bounds checking allows an attacker to overwrite adjacent memory locations including return addresses and control data structures.
The operational impact of this vulnerability extends beyond simple code execution, as it provides remote attackers with complete system compromise capabilities through the fax conversion process. When a malicious text file containing carefully crafted overflow data is processed by 2fax 3.04, the buffer overflow can be leveraged to overwrite the program's execution flow, allowing attackers to inject and execute arbitrary code with the privileges of the 2fax process. This creates a significant risk for systems that automatically process incoming fax documents or handle untrusted text files during conversion. The vulnerability can be exploited remotely through various means including email attachments, web uploads, or any method that results in the text file being processed by the vulnerable fax conversion utility. The attack vector aligns with ATT&CK technique T1203, which covers exploitation of remote services, and T1059, covering command and scripting interpreters, as the execution of arbitrary code can occur through the normal processing of text files.
Mitigation strategies for CVE-2004-1255 must address both the immediate vulnerability and broader system security posture. The primary recommendation involves upgrading to a patched version of 2fax or replacing the vulnerable software with a more secure alternative that properly implements input validation and buffer management. System administrators should also implement strict input validation controls, including size limitations and character set restrictions for text files processed by fax utilities. Network segmentation and access controls should be enforced to limit exposure of fax processing systems to untrusted networks and users. Additionally, monitoring systems should be configured to detect unusual patterns in fax processing activities that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and memory safety practices in software development, particularly for applications handling untrusted data from external sources, and aligns with security best practices outlined in the OWASP Top Ten and NIST cybersecurity guidelines for buffer overflow prevention. Organizations should also consider implementing runtime protections such as stack canaries, address space layout randomization, and data execution prevention mechanisms to reduce the impact of similar vulnerabilities in other software components.