CVE-2017-17996 in SyncBreeze Enterprise
Summary
by MITRE
A buffer overflow vulnerability in "Add command" functionality exists in Flexense SyncBreeze Enterprise <= 10.3.14. The vulnerability can be triggered by an authenticated attacker who submits more than 5000 characters as the command name. It will cause termination of the SyncBreeze Enterprise server and possibly remote command execution with SYSTEM privilege.
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Analysis
by VulDB Data Team • 01/02/2020
The vulnerability identified as CVE-2017-17996 represents a critical buffer overflow flaw within Flexense SyncBreeze Enterprise version 10.3.14 and earlier. This issue resides in the "Add command" functionality of the synchronization software, which is designed to manage and execute various file synchronization tasks. The flaw manifests when the application fails to properly validate input length during command creation, creating an exploitable condition that can be leveraged by malicious actors. The vulnerability specifically targets the command name parameter, which serves as the primary input field for defining new synchronization commands within the enterprise environment. This represents a fundamental failure in input validation and memory management practices, creating a pathway for arbitrary code execution that can escalate to system-level privileges.
The technical exploitation of this vulnerability follows a well-established pattern of buffer overflow attacks where an attacker submits an excessive input string exceeding 5000 characters to the command name field. This oversized input causes the application's memory buffer to overflow, leading to unpredictable behavior including application crashes, memory corruption, and potential code execution. The overflow occurs in the application's memory management routines where the fixed-size buffer allocated for command names cannot accommodate the excessive input length. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflows. The memory corruption resulting from this overflow can be manipulated to overwrite critical program execution pointers, function return addresses, or other control data structures, enabling attackers to redirect program flow and execute malicious code.
The operational impact of this vulnerability extends beyond simple service disruption to encompass complete system compromise. When the SyncBreeze Enterprise server terminates due to the buffer overflow, it creates a denial of service condition that can disrupt critical file synchronization operations across enterprise networks. However, the more severe implications arise from the potential for remote code execution with SYSTEM privileges, which represents a complete compromise of the affected system. Attackers who successfully exploit this vulnerability can gain administrative control over the synchronization server, potentially accessing sensitive data, modifying synchronization rules, or using the compromised system as a pivot point for further attacks within the network. The enterprise environment is particularly vulnerable as SyncBreeze servers often run with elevated privileges to perform file operations, making the privilege escalation aspect especially dangerous. This vulnerability directly maps to ATT&CK technique T1059, which covers command and scripting interpreter, and T1068, which addresses exploit for privilege escalation.
Mitigation strategies for CVE-2017-17996 should prioritize immediate patching of affected systems to address the underlying buffer overflow condition. Organizations must implement input validation controls that enforce strict limits on command name length, ensuring that no single input exceeds predetermined safe thresholds. Network segmentation and access controls should be implemented to limit the attack surface, restricting unauthorized access to the SyncBreeze Enterprise management interface. Regular security assessments and vulnerability scanning should be conducted to identify similar buffer overflow conditions in other enterprise applications. The implementation of application whitelisting and runtime application control measures can provide additional defense-in-depth layers to prevent exploitation of similar vulnerabilities. Organizations should also establish incident response procedures specifically designed to handle buffer overflow exploitation attempts and ensure proper monitoring of system logs for signs of exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and memory management practices in enterprise software development, highlighting the need for comprehensive security testing throughout the software development lifecycle to prevent such conditions from reaching production environments.