CVE-2000-0852 in FreeBSD
Summary
by MITRE
Multiple buffer overflows in eject on FreeBSD and possibly other OSes allows local users to gain root privileges.
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Analysis
by VulDB Data Team • 05/27/2018
The vulnerability described in CVE-2000-0852 represents a critical security flaw in the eject utility across FreeBSD and potentially other operating systems. This issue stems from improper input validation within the eject command implementation, creating conditions where maliciously crafted input can trigger buffer overflow conditions. The vulnerability specifically affects the eject utility which is commonly used to safely remove removable media such as floppy disks, CDs, or DVDs from system drives. When a local user executes the vulnerable eject command with specially crafted arguments, the program fails to properly bounds-check input data before copying it into fixed-size buffers, leading to memory corruption that can be exploited for privilege escalation.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers stack-based buffer overflow scenarios. These buffer overflows occur because the eject utility does not validate the length of input parameters before processing them, allowing attackers to overwrite adjacent memory locations including return addresses and control data. The flaw operates at the system level where local users can leverage this vulnerability to execute arbitrary code with elevated privileges, potentially gaining root access to the affected system. The exploitation mechanism relies on the attacker controlling the program flow by overwriting critical memory locations, effectively allowing code execution with the highest system privileges.
The operational impact of CVE-2000-0852 extends beyond simple privilege escalation as it provides attackers with complete system compromise capabilities. Local users who can execute the eject command gain the ability to elevate their privileges to root level, which can lead to unauthorized access to sensitive system files, modification of system configurations, installation of backdoors, and potential lateral movement within network environments. This vulnerability particularly affects Unix-like systems where the eject utility is commonly used for media management, making it a significant concern for system administrators managing multiple user environments. The local nature of the exploit means that any user with access to the system can potentially leverage this flaw, regardless of their initial privilege level, making it a particularly dangerous vulnerability in multi-user environments.
Mitigation strategies for this vulnerability include immediate patching of the eject utility to implement proper input validation and bounds checking. System administrators should ensure that all FreeBSD systems and similar Unix-based operating systems receive updates that address the buffer overflow conditions in the eject command. Additionally, implementing the principle of least privilege can help reduce the impact of such vulnerabilities by limiting user access to system utilities and ensuring that only authorized personnel have the ability to execute potentially dangerous commands. The MITRE ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the execution of malicious code with elevated privileges. Regular security audits and input validation testing should be implemented to identify similar buffer overflow conditions in other system utilities and applications, as this represents a common class of vulnerabilities that can lead to system compromise. Organizations should also consider implementing runtime protections and monitoring systems that can detect anomalous behavior patterns associated with buffer overflow exploitation attempts.