CVE-2000-0055 in Solaris
Summary
by MITRE
Buffer overflow in Solaris chkperm command allows local users to gain root access via a long -n option.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability identified as CVE-2000-0055 represents a critical buffer overflow flaw in the Solaris chkperm command that enables local attackers to escalate privileges to root access. This vulnerability resides within the command line parsing mechanism of the chkperm utility, which is part of the Solaris operating system's file permission checking framework. The issue manifests specifically when processing the -n option, where insufficient input validation allows an attacker to provide an excessively long argument that overflows the allocated buffer space. This buffer overflow condition creates an exploitable memory corruption vulnerability that can be leveraged to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The chkperm command's handling of the -n option fails to properly validate the length of user-supplied input before copying it into a fixed-size buffer, creating a classic stack buffer overflow scenario. When the command processes a sufficiently long -n argument, it overwrites the return address on the stack, allowing an attacker to redirect program execution flow to malicious code. This vulnerability operates entirely within the local privilege escalation category, as it requires local system access but does not depend on network connectivity or remote exploitation vectors.
The operational impact of CVE-2000-0055 is significant for Solaris systems, as it provides a straightforward path for local attackers to achieve root compromise without requiring special privileges or network access. Once exploited, the vulnerability allows attackers to gain complete system control, enabling them to modify system files, install backdoors, steal sensitive data, or establish persistent access to the compromised system. The attack vector is particularly concerning because it requires minimal privileges to exploit and can be executed by any local user who has access to the chkperm command. This makes the vulnerability particularly dangerous in multi-user environments where local access might be more readily available than remote access, and it represents a common attack pattern that aligns with the ATT&CK technique T1068, which covers privilege escalation through local exploitation.
Mitigation strategies for this vulnerability should include immediate patching of affected Solaris systems through official Oracle security updates, which would address the buffer overflow by implementing proper input validation and bounds checking. System administrators should also implement additional security controls such as restricting local user access to the chkperm command where possible, implementing proper privilege separation, and monitoring for unusual command execution patterns. The vulnerability demonstrates the importance of input validation in system utilities and highlights the need for proper security testing of command line tools that handle user-supplied arguments. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and should conduct regular vulnerability assessments to identify similar buffer overflow conditions in other system components. Additionally, the use of modern security features such as stack canaries, address space layout randomization, and non-executable stack protections can provide additional defense in depth against similar buffer overflow exploitation attempts.