CVE-2017-4989 in Avamar Server
Summary
by MITRE
In EMC Avamar Server Software 7.3.1-125, 7.3.0-233, 7.3.0-226, 7.2.1-32, 7.2.1-31, 7.2.0-401, an unauthenticated remote attacker may potentially bypass the authentication process to gain access to the system maintenance page. This may be exploited by an attacker to view sensitive information, perform software updates, or run maintenance workflows.
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Analysis
by VulDB Data Team • 12/29/2020
The vulnerability identified as CVE-2017-4989 represents a critical authentication bypass flaw in EMC Avamar Server Software across multiple versions including 7.3.1-125, 7.3.0-233, 7.3.0-226, 7.2.1-32, 7.2.1-31, and 7.2.0-401. This weakness falls under the CWE-287 category of Improper Authentication, specifically manifesting as an insufficient authentication mechanism that allows unauthenticated attackers to access protected system maintenance interfaces. The vulnerability stems from improper validation of authentication tokens or session management within the web application layer of the Avamar server software, creating an exploitable path for malicious actors to bypass the standard authentication requirements.
The technical implementation of this flaw enables remote attackers to directly access the system maintenance page without providing valid credentials, fundamentally undermining the security model of the software. This authentication bypass occurs at the application level where the software fails to properly verify user identity before granting access to administrative functions. The vulnerability is particularly concerning because it affects the maintenance interface, which typically contains sensitive operational controls and system configuration options. Attackers can leverage this weakness to perform unauthorized actions including viewing sensitive system information, executing software updates, and running maintenance workflows that could compromise system integrity and availability.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential system compromise and data exposure. An attacker exploiting this vulnerability could gain the ability to modify system configurations, install malicious software, or extract confidential data from the Avamar backup infrastructure. The maintenance page typically contains critical system parameters and operational controls that when compromised can lead to complete system takeover or data loss. This vulnerability aligns with ATT&CK technique T1078.004 for Valid Accounts and T1566.001 for Phishing, as it enables attackers to bypass authentication mechanisms and potentially escalate privileges through legitimate administrative interfaces. The exposure of system maintenance functions provides attackers with direct access to operational controls that could be used to disrupt services or manipulate backup operations.
Organizations running affected EMC Avamar Server Software versions face significant security risks including unauthorized system modification, data exfiltration, and potential disruption of backup operations. The vulnerability's remote exploitability means attackers can target systems without requiring physical access or prior authentication credentials. Recommended mitigations include immediate application of vendor security patches, network segmentation to isolate critical backup infrastructure, and implementation of additional access controls such as firewall rules restricting access to maintenance interfaces. The vulnerability demonstrates the importance of proper authentication implementation and highlights the need for regular security assessments of backup and recovery systems. Organizations should also implement monitoring solutions to detect unauthorized access attempts to administrative interfaces and establish incident response procedures for potential exploitation of authentication bypass vulnerabilities.