CVE-2014-3074 in AIX
Summary
by MITRE
The runtime linker in IBM AIX 6.1 and 7.1 and VIOS 2.2.x allows local users to create a mode-666 root-owned file, and consequently gain privileges, by setting crafted MALLOCOPTIONS and MALLOCBUCKETS environment-variable values and then executing a setuid program.
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Analysis
by VulDB Data Team • 12/17/2024
The vulnerability described in CVE-2014-3074 represents a critical privilege escalation flaw within the runtime linker component of IBM AIX operating systems and VIOS environments. This issue affects versions 6.1 and 7.1 of AIX along with VIOS 2.2.x releases, demonstrating how improper environment variable handling can lead to severe security implications. The vulnerability operates through a sophisticated attack vector that leverages the interaction between memory allocation parameters and setuid program execution to achieve unauthorized privilege elevation.
The technical exploitation mechanism centers on the manipulation of two specific environment variables: MALLOCOPTIONS and MALLOCBUCKETS. These variables control memory allocation behavior within the runtime linker, and when set to crafted values, they can influence how the system handles file creation operations. The flaw occurs because the runtime linker does not properly validate or sanitize these environment variables before using them in contexts where file operations are performed. When a setuid program executes with these maliciously configured variables, the linker's memory management routines create files with world-writable permissions (mode 666) that are owned by the root user, effectively creating a backdoor for privilege escalation.
The operational impact of this vulnerability is severe and directly aligns with CWE-276, which addresses improper file permissions. Attackers can exploit this weakness to create arbitrary files with root ownership, potentially allowing them to modify system-critical components or establish persistent access mechanisms. The vulnerability particularly affects systems where users can execute setuid programs, as these programs typically run with elevated privileges and can be leveraged to perform the file creation operations that lead to privilege escalation. The attack requires local system access but provides a pathway to root-level compromise that can be exploited by malicious users or attackers who have already gained initial access to the system.
This vulnerability demonstrates characteristics consistent with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation." The flaw enables attackers to leverage existing system processes to gain higher privileges, making it particularly dangerous in enterprise environments where setuid programs are commonly used for system administration tasks. Organizations should consider this vulnerability as part of a broader privilege escalation attack surface and implement comprehensive monitoring for suspicious file creation patterns. The attack vector is particularly concerning because it can be executed without requiring network access or specialized tools beyond the ability to set environment variables and execute existing system programs. Security teams should prioritize patching affected systems and implement strict monitoring of environment variable usage in conjunction with setuid program execution to prevent exploitation of this class of vulnerability.