CVE-1999-1371 in Solaris
Summary
by MITRE
Buffer overflow in /usr/bin/write in Solaris 2.6 and 7 allows local users to gain privileges via a long string in the terminal name argument.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/29/2024
The vulnerability described in CVE-1999-1371 represents a classic buffer overflow flaw located within the /usr/bin/write utility in Solaris 2.6 and 2.7 operating systems. This particular implementation flaw exists in the handling of terminal name arguments, where the program fails to properly validate input length before copying data into fixed-size buffers. The write command is designed to allow users to send messages to other logged-in users, but when a malicious user provides an excessively long terminal name argument, the program's buffer handling mechanism becomes compromised.
The technical implementation of this vulnerability stems from improper bounds checking within the write utility's argument parsing code. When the program processes the terminal name argument, it attempts to store this input into a predetermined buffer without adequate length verification. This condition creates an exploitable scenario where the overflow can overwrite adjacent memory locations including return addresses, stack canaries, or other critical program data. The vulnerability specifically affects local users who have access to the system, making it a privilege escalation vector that can potentially allow attackers to execute arbitrary code with elevated privileges. According to CWE classification, this represents a classic buffer overflow vulnerability categorized under CWE-121, which deals with stack-based buffer overflow conditions.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with a mechanism to gain elevated system access through local means. Since the write utility is typically accessible to all users on the system, an attacker can leverage this flaw without requiring remote network access or special authentication credentials. The privilege escalation potential allows local users to potentially execute code with the privileges of the target user or even root access depending on how the system is configured. This vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and demonstrates how local exploitation techniques can be used to gain higher system privileges. The attack surface is particularly concerning as it involves a standard system utility that is frequently used for communication between users, making it a common target for exploitation.
Mitigation strategies for CVE-1999-1371 should focus on both immediate patching and system hardening measures. The primary solution involves applying the appropriate security patches released by Sun Microsystems for Solaris 2.6 and 2.7 systems, which correct the buffer overflow condition in the write utility. System administrators should also implement input validation controls and consider disabling unnecessary user access to the write command where possible. Additionally, implementing stack protection mechanisms and address space layout randomization can provide additional defense-in-depth measures against exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation and buffer management in system utilities, particularly those that handle user-provided data. Organizations should conduct regular security assessments of their system utilities and ensure that all software components undergo rigorous testing for memory safety vulnerabilities to prevent similar issues from arising in modern systems.