CVE-2005-4273 in AIX
Summary
by MITRE
multiple unspecified vulnerabilities in (1) getshell and (2) getcommand in ibm aix 5.3 allow local users to append to arbitrary files.
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Analysis
by VulDB Data Team • 01/14/2018
The vulnerability identified as CVE-2005-4273 affects IBM AIX 5.3 systems and involves multiple unspecified security flaws within the getshell and getcommand utilities. These utilities are part of the operating system's command execution framework and are designed to handle shell command processing. The specific nature of the vulnerabilities remains undisclosed in the public CVE database, which is common for certain legacy vulnerabilities where the exact technical details were not fully documented in the initial reporting. This lack of specificity makes the vulnerability particularly concerning as it suggests potential for widespread impact across multiple attack vectors within the affected system components.
The core technical flaw lies in the improper handling of file operations within these utilities, specifically allowing local users to append data to arbitrary files on the system. This represents a significant privilege escalation risk as local attackers can leverage these utilities to modify system files, potentially leading to persistent access or system compromise. The ability to append to arbitrary files indicates a lack of proper input validation and access control mechanisms within the getshell and getcommand functions. This type of vulnerability typically falls under CWE-22, which describes improper limitation of a pathname to a restricted directory, and may also relate to CWE-73, which covers external control of file name or path. The attack vector specifically enables local privilege escalation through file manipulation, allowing an attacker with minimal system access to potentially gain more extensive control over the system's file structure.
The operational impact of CVE-2005-4273 extends beyond simple file manipulation capabilities as it provides attackers with a method to establish persistent access or corrupt critical system files. Local users who can execute these utilities may use the vulnerability to modify system configuration files, log files, or even critical binaries, potentially leading to system instability or complete compromise. The vulnerability affects the fundamental security model of AIX 5.3 by allowing local users to bypass normal file access controls and append data to files they would not normally be able to modify. This weakness particularly impacts systems where local users may have legitimate access to these utilities but should not have the ability to modify arbitrary files within the system. The vulnerability represents a critical flaw in the principle of least privilege enforcement, where proper access controls fail to prevent unauthorized file modifications.
Mitigation strategies for this vulnerability should focus on immediate system hardening and access control improvements. System administrators should implement strict file permissions and access controls to limit which users can execute getshell and getcommand utilities. The most effective immediate response involves disabling or removing unnecessary access to these utilities from non-privileged accounts. Additionally, implementing proper input validation and sanitization within the affected utilities would prevent the arbitrary file append functionality. Organizations should also consider implementing file integrity monitoring solutions to detect unauthorized file modifications. According to ATT&CK framework, this vulnerability maps to T1068, which covers 'Exploitation for Privilege Escalation', and T1078, covering 'Valid Accounts'. The vulnerability essentially allows attackers to leverage local accounts to escalate privileges through file manipulation. Patch management should be prioritized to address the root cause, while system monitoring should be enhanced to detect any attempts to exploit this weakness through file modification activities. Regular security assessments should verify that access controls are properly enforced and that no unauthorized modifications have occurred.