CVE-2002-1381 in Exim
Summary
by MITRE
Format string vulnerability in daemon.c for Exim 4.x through 4.10, and 3.x through 3.36, allows exim administrative users to execute arbitrary code by modifying the pid_file_path value.
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Analysis
by VulDB Data Team • 11/20/2024
The vulnerability identified as CVE-2002-1381 represents a critical format string vulnerability within the Exim email server software that affects versions ranging from 3.x through 3.36 and 4.x through 4.10. This flaw exists in the daemon.c component of the software, which is responsible for managing the daemon processes that handle email delivery operations. The vulnerability specifically manifests when administrative users modify the pid_file_path configuration value, creating a pathway for malicious code execution through improper input validation and format string handling.
The technical exploitation of this vulnerability occurs through a classic format string attack vector where the pid_file_path parameter is not properly sanitized before being processed by a printf-like function. When an administrator modifies this configuration value, the software fails to validate the input against format string specifiers such as %s, %d, or %x, allowing attackers to inject malicious format specifiers that can lead to memory corruption and arbitrary code execution. This particular vulnerability falls under the CWE-134 classification of format string vulnerabilities, which are categorized as weaknesses in software that improperly handles format strings in functions like printf, sprintf, or fprintf.
The operational impact of this vulnerability is severe as it provides a direct path for privilege escalation and remote code execution within the context of the Exim daemon process. Administrative users who can modify configuration parameters are essentially granting attackers the ability to execute arbitrary code with the privileges of the Exim service account, which typically runs with elevated system permissions. This vulnerability can be exploited to gain full control over the email server, potentially leading to data exfiltration, server compromise, and use as a pivot point for attacking other systems within the network infrastructure. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the execution of malicious code through configuration manipulation and format string exploitation.
Mitigation strategies for CVE-2002-1381 should focus on immediate patching of affected Exim versions to the latest stable releases that contain proper input validation and format string handling. System administrators should implement strict access controls limiting who can modify configuration files, particularly those related to daemon processes and file paths. Additionally, monitoring for unusual modifications to the pid_file_path configuration parameter should be implemented through log analysis and intrusion detection systems. The vulnerability demonstrates the critical importance of proper input validation and secure coding practices, particularly when dealing with user-supplied data that may be passed to formatting functions. Organizations should also consider implementing application whitelisting policies and regular security audits to identify similar vulnerabilities in legacy software components that may not receive ongoing security updates.