CVE-2001-0588 in Sendmail
Summary
by MITRE
sendmail 8.9.3, as included with the MMDF 2.43.3b package in SCO OpenServer 5.0.6, can allow a local attacker to gain additional privileges via a buffer overflow in the first argument to the command.
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Analysis
by VulDB Data Team • 06/27/2021
The vulnerability described in CVE-2001-0588 represents a critical buffer overflow flaw within the sendmail 8.9.3 implementation distributed with SCO OpenServer 5.0.6. This issue specifically affects the MMDF 2.43.3b package and creates a privilege escalation vector that allows local attackers to execute malicious code with elevated permissions. The vulnerability stems from improper input validation in the command processing mechanism where the first argument to the sendmail command is handled without adequate bounds checking.
The technical exploitation of this buffer overflow occurs when a local user provides a specially crafted argument string that exceeds the allocated buffer size in the sendmail binary. This overflow can overwrite adjacent memory locations including return addresses and control data structures, potentially allowing an attacker to redirect program execution flow. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which is a common class of memory corruption vulnerabilities that can lead to arbitrary code execution. The flaw specifically impacts the command line argument parsing functionality of sendmail, making it particularly dangerous as it can be triggered through normal program usage patterns.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data integrity breaches. Local attackers who can execute commands on the system can leverage this vulnerability to gain root privileges or elevate their existing access level to administrative capabilities. This creates a significant risk for systems where sendmail is running with elevated privileges, as it provides a pathway for unauthorized users to bypass security controls and access sensitive system resources. The vulnerability affects systems running SCO OpenServer 5.0.6 which was a commercial unix variant, and represents a typical attack surface for privilege escalation techniques.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through local exploits, and T1059 which encompasses command and scripting interpreters. The attack vector is particularly concerning as it requires only local access to exploit, making it accessible to users who may have legitimate access to the system but lack administrative privileges. Mitigation strategies should include immediate patching of the sendmail package to version 8.9.4 or later which contains the necessary buffer overflow protections. System administrators should also implement privilege separation mechanisms and ensure that sendmail is not running with unnecessary elevated privileges. Additionally, monitoring for unusual command execution patterns and implementing proper input validation controls can help detect and prevent exploitation attempts. The vulnerability demonstrates the importance of proper bounds checking in system utilities and highlights the need for regular security updates to address known memory corruption issues that can lead to complete system compromise.