CVE-2018-6329 in Backup
Summary
by MITRE
It was discovered that the Unitrends Backup (UB) before 10.1.0 libbpext.so authentication could be bypassed with a SQL injection, allowing a remote attacker to place a privilege escalation exploit on the target system and subsequently execute arbitrary commands.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2018-6329 represents a critical authentication bypass flaw within Unitrends Backup software versions prior to 10.1.0. This issue resides in the libbpext.so library component which handles authentication processes for the backup system. The vulnerability stems from improper input validation mechanisms that fail to adequately sanitize user-supplied data before processing within the authentication framework. Attackers can exploit this weakness through carefully crafted SQL injection payloads that manipulate the authentication logic to bypass normal security controls.
The technical implementation of this vulnerability demonstrates a classic SQL injection attack vector that specifically targets the authentication module of the backup system. When the libbpext.so library processes authentication requests, it fails to properly escape or validate input parameters that are directly incorporated into SQL queries. This allows malicious actors to inject arbitrary SQL commands that can manipulate the database queries used for user authentication. The flaw operates at the application layer where the backup system's authentication service processes login attempts without sufficient sanitization of input data.
The operational impact of this vulnerability extends beyond simple authentication bypass to enable full privilege escalation capabilities within the target system. Once authenticated, an attacker can leverage the bypass to gain administrative privileges and subsequently deploy malicious payloads that can execute arbitrary commands on the compromised system. This represents a severe escalation path that transforms a remote authentication bypass into a complete system compromise. The vulnerability affects the entire Unitrends Backup infrastructure and could potentially provide attackers with access to sensitive backup data and system configurations.
Security professionals should recognize this vulnerability as a direct manifestation of CWE-89 SQL Injection, which falls under the broader category of injection flaws that represent one of the most prevalent security weaknesses in web applications and system components. The attack vector aligns with ATT&CK technique T1078 Valid Accounts, where adversaries leverage compromised or bypassed authentication mechanisms to maintain persistent access to systems. Additionally, this vulnerability demonstrates characteristics of T1059 Command and Scripting Interpreter, as the exploitation chain ultimately enables arbitrary command execution on the target system. Organizations should implement immediate mitigations including upgrading to Unitrends Backup version 10.1.0 or later, implementing network segmentation to limit access to backup systems, and conducting thorough security assessments of all backup infrastructure components. The vulnerability also highlights the importance of input validation and parameterized queries in preventing injection attacks across all system components.