CVE-2009-0849 in NovaNET
Summary
by MITRE
Stack-based buffer overflow in the DtbClsLogin function in NovaStor NovaNET 12 allows remote attackers to (1) execute arbitrary code on Linux platforms via a long username field during backup domain authentication, related to libnnlindtb.so; or (2) cause a denial of service (daemon crash) on Windows platforms via a long username field during backup domain authentication, related to nnwindtb.dll. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 11/16/2025
The vulnerability identified as CVE-2009-0849 represents a critical stack-based buffer overflow in the NovaStor NovaNET 12 backup software suite, specifically within the DtbClsLogin function. This flaw exists in two distinct implementations across different operating systems, demonstrating the complexity of cross-platform security vulnerabilities. The vulnerability is particularly concerning because it affects the core authentication mechanism of the backup domain, making it a prime target for exploitation by malicious actors seeking unauthorized access to backup systems. The affected components include libnnlindtb.so on Linux platforms and nnwindtb.dll on Windows platforms, both of which handle user authentication during backup domain operations.
The technical implementation of this vulnerability stems from inadequate input validation within the DtbClsLogin function, which fails to properly bounds-check the username field provided during authentication. When a maliciously crafted username exceeding the allocated stack buffer size is submitted, it overflows into adjacent memory locations, potentially corrupting program execution flow. This type of vulnerability maps directly to CWE-121, which categorizes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent stack data. The overflow can be exploited to overwrite return addresses, function pointers, or other critical program variables, enabling arbitrary code execution on Linux systems or causing daemon crashes on Windows platforms.
From an operational perspective, this vulnerability presents significant risks to enterprise backup infrastructure security and availability. Attackers exploiting this flaw can gain unauthorized access to backup domains, potentially compromising entire backup repositories and sensitive organizational data. The remote attack vector eliminates the need for physical access or local network presence, making the vulnerability particularly dangerous in networked environments. On Linux systems, successful exploitation could result in complete system compromise, while Windows systems face denial of service conditions that could disrupt backup operations and potentially create data loss scenarios. The impact extends beyond immediate exploitation as compromised backup systems can serve as persistent entry points for broader network infiltration.
The attack surface for this vulnerability is primarily through backup domain authentication mechanisms, making it particularly dangerous in environments where backup systems are exposed to untrusted networks or where administrative credentials are compromised. Organizations using NovaNET 12 should consider this vulnerability in their threat modeling exercises, particularly when evaluating backup infrastructure security. The dual nature of the vulnerability - providing both execution capabilities on Linux and denial of service on Windows - requires comprehensive mitigation strategies across platform boundaries. Security teams should implement network segmentation to limit access to backup domains and consider monitoring for unusual authentication patterns that might indicate exploitation attempts. Additionally, the vulnerability demonstrates the importance of input validation in authentication systems and highlights the need for regular security assessments of backup and recovery infrastructure components.
Mitigation strategies should include immediate patching of affected NovaNET 12 installations, implementing network access controls to restrict backup domain authentication to trusted sources, and deploying intrusion detection systems to monitor for exploitation attempts. Organizations should also consider implementing authentication logging and monitoring to detect unusual username lengths or patterns that might indicate buffer overflow attempts. The vulnerability serves as a reminder of the critical importance of secure coding practices, particularly in authentication and input handling components, and aligns with ATT&CK techniques related to privilege escalation and defense evasion through exploitation of software vulnerabilities. System administrators should also review backup system configurations to ensure that authentication mechanisms are properly hardened against buffer overflow attacks and that appropriate access controls are implemented to limit the potential impact of successful exploitation attempts.