CVE-2018-15331 in BIG-IP AAM
Summary
by MITRE
On BIG-IP AAM 13.0.0 or 12.1.0-12.1.3.7, the dcdb_convert utility used by BIG-IP AAM fails to drop group permissions when executing helper scripts, which could be used to leverage attacks against the BIG-IP system.
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Analysis
by VulDB Data Team • 06/20/2023
The vulnerability identified as CVE-2018-15331 affects F5 BIG-IP Application Acceleration Manager versions 12.1.0 through 12.1.3.7 and 13.0.0, specifically targeting the dcdb_convert utility component. This utility serves as a helper script execution mechanism within the AAM module responsible for processing database conversions and related administrative tasks. The flaw represents a critical privilege escalation vulnerability that stems from improper privilege management during script execution processes.
The technical implementation of this vulnerability resides in the dcdb_convert utility's failure to properly drop group permissions when executing helper scripts. When the utility processes administrative operations, it inherits and maintains elevated group privileges that should be stripped before executing potentially untrusted helper scripts. This design flaw creates an opportunity for malicious actors to exploit the inherited permissions and execute unauthorized operations with elevated privileges. The vulnerability specifically impacts the principle of least privilege enforcement, where the system fails to properly constrain the execution context of helper scripts.
From an operational standpoint, this vulnerability presents a significant risk to BIG-IP system integrity and security posture. Attackers who can successfully exploit this flaw could leverage the elevated group permissions to execute arbitrary code, modify system configurations, access sensitive data, or establish persistent access within the network infrastructure. The impact extends beyond simple privilege escalation as it potentially allows for broader system compromise and can serve as a foothold for further attacks within the network environment. This vulnerability directly aligns with CWE-276, which addresses improper privilege management and inadequate privilege dropping mechanisms in system components.
The exploitation of this vulnerability typically requires an attacker to first gain access to a system with the ability to trigger the dcdb_convert utility execution path. Once triggered, the inherited group permissions can be leveraged to execute malicious helper scripts that would otherwise be restricted. This creates a pathway for attackers to perform operations that should be limited to specific administrative users or system processes. The attack vector often involves manipulating input parameters that lead to the execution of the vulnerable utility, making it a significant concern for systems with exposed administrative interfaces.
Organizations should implement immediate mitigations including applying the official F5 security patches released for this vulnerability, which address the privilege dropping mechanism in the dcdb_convert utility. Network segmentation and access controls should be strengthened to limit exposure of BIG-IP systems to untrusted networks. Additionally, monitoring should be implemented to detect unusual execution patterns of helper scripts and privilege escalation attempts. The vulnerability demonstrates the critical importance of proper privilege management and privilege dropping mechanisms in security-critical applications, aligning with ATT&CK technique T1068 which covers privilege escalation through local exploits. Regular security assessments and privilege reviews should be conducted to ensure that similar issues do not exist in other system components, particularly those handling administrative script execution.