CVE-2005-0816 in Solaris
Summary
by MITRE
Buffer overflow in newgrp in Solaris 7 through 9 allows local users to gain root privileges.
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Analysis
by VulDB Data Team • 07/01/2021
The vulnerability identified as CVE-2005-0816 represents a critical buffer overflow flaw within the newgrp utility of Solaris operating systems versions 7 through 9. This issue resides in the group membership management functionality that allows users to switch to different groups while maintaining their session context. The newgrp command serves as a fundamental component for user group administration in Unix-like systems, making it a prime target for privilege escalation attacks. The flaw specifically manifests when the command processes group names that exceed predetermined buffer limits, creating a condition where arbitrary memory locations can be overwritten through carefully crafted input sequences. This vulnerability operates at the system level and directly impacts the security model of Solaris systems by providing a pathway for local attackers to bypass normal access controls and elevate their privileges to the root level.
The technical implementation of this buffer overflow stems from inadequate input validation within the newgrp utility's string handling routines. When users execute newgrp with a group name exceeding the allocated buffer space, the command fails to properly check input boundaries before copying data into memory. This classic buffer overflow condition allows attackers to overwrite adjacent memory locations including return addresses and control data structures. The vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and specifically aligns with CWE-122, which addresses heap-based buffer overflows. Attackers can exploit this flaw by crafting malicious group names that overwrite the program's execution flow, ultimately redirecting control to malicious code or existing system binaries with elevated privileges. The attack vector is local in nature, requiring physical or network access to the target system, but the consequences are severe as successful exploitation results in complete system compromise.
The operational impact of CVE-2005-0816 extends beyond simple privilege escalation to encompass complete system compromise and potential data exfiltration capabilities. Once an attacker achieves root privileges through this vulnerability, they gain unrestricted access to all system resources, including the ability to modify system files, install backdoors, monitor network traffic, and access sensitive user data. The vulnerability affects the core authentication and authorization mechanisms of Solaris systems, undermining the fundamental security assumptions that protect system integrity. From an adversary perspective, this flaw provides an ideal entry point for persistent access, as the elevated privileges enable attackers to establish footholds that persist across system reboots and are difficult to detect through standard monitoring approaches. The vulnerability also demonstrates the importance of proper input validation in system utilities, as the flaw exists in a utility that is frequently used during normal system operations, making detection more challenging for security monitoring systems.
Mitigation strategies for CVE-2005-0816 must address both immediate remediation and long-term security hardening measures. The primary solution involves applying the official security patches released by Sun Microsystems for affected Solaris versions, which include buffer size modifications and input validation enhancements to prevent the overflow condition. System administrators should also implement additional security controls such as restricting access to the newgrp command through file permissions and ensuring that only trusted users have the ability to execute it. Network segmentation and monitoring should be enhanced to detect unusual patterns of group membership changes that might indicate exploitation attempts. From a defensive standpoint, this vulnerability highlights the necessity of maintaining up-to-date system patches and implementing comprehensive security monitoring that can detect anomalous behavior in system utilities. The flaw also reinforces the ATT&CK framework concept of privilege escalation through local exploitation, specifically mapping to techniques involving command execution and credential access. Organizations should consider implementing automated patch management systems to prevent similar vulnerabilities from remaining unaddressed, as this particular flaw represents a well-known exploit that has been documented since 2005 and continues to pose risks in legacy systems.