CVE-2016-0920 in Avamar Server
Summary
by MITRE
Avamar Data Store (ADS) and Avamar Virtual Edition (AVE) in EMC Avamar Server before 7.3.0-233 allow local users to obtain root access via a crafted parameter to a command that is available in the sudo configuration.
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Analysis
by VulDB Data Team • 09/19/2022
The vulnerability identified as CVE-2016-0920 affects EMC Avamar Server components including Avamar Data Store and Avamar Virtual Edition across versions prior to 7.3.0-233. This represents a critical privilege escalation flaw that enables local attackers to escalate their privileges from standard user level to root access. The vulnerability stems from improper input validation within a command that is configured to run with sudo privileges, creating an exploitable path for unauthorized privilege elevation.
The technical implementation of this vulnerability involves a crafted parameter being passed to a command that has been configured in the sudoers file with elevated privileges. When the system processes this malicious input, it fails to properly sanitize or validate the parameter before executing the command, allowing the attacker to inject additional commands or manipulate the execution context. This type of flaw falls under the Common Weakness Enumeration category CWE-20, which specifically addresses improper input validation, and more broadly relates to CWE-264, which covers permissions, privileges, and access control weaknesses.
From an operational impact perspective, this vulnerability presents a severe risk to organizations relying on EMC Avamar systems for data protection and backup operations. Local users who can access the system with basic credentials can exploit this flaw to gain root access, potentially compromising the entire backup infrastructure. The implications extend beyond simple privilege escalation as root access provides complete control over the system, including the ability to modify backup configurations, access sensitive data, and potentially disrupt backup operations that are critical for business continuity. This vulnerability directly aligns with ATT&CK technique T1068, which covers local privilege escalation, and T1566, which involves social engineering through the exploitation of system vulnerabilities.
Organizations should immediately implement the vendor-provided patch for EMC Avamar Server version 7.3.0-233 to address this vulnerability. System administrators should also conduct thorough security audits to identify any other potentially vulnerable sudo configurations within the environment. Additional mitigations include implementing least privilege principles for sudo access, regularly reviewing sudoers file configurations, and monitoring for suspicious command executions. The vulnerability demonstrates the critical importance of proper input validation in privileged execution contexts and serves as a reminder of the potential for seemingly minor configuration flaws to result in complete system compromise. Organizations should also consider implementing additional security controls such as privilege access management tools and regular security assessments to prevent similar vulnerabilities from being exploited in other system components.