CVE-2007-2894 in Bochs
Summary
by MITRE
The emulated floppy disk controller in Bochs 2.3 allows local users of the guest operating system to cause a denial of service (virtual machine crash) via unspecified vectors, resulting in a divide-by-zero error.
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Analysis
by VulDB Data Team • 12/14/2024
The vulnerability identified as CVE-2007-2894 resides within the Bochs 2.3 virtualization platform, specifically within its emulated floppy disk controller implementation. This represents a critical flaw in virtual machine emulation that demonstrates how hardware component emulation can introduce security risks even in well-established virtualization software. The vulnerability affects users who operate guest operating systems within Bochs virtual environments, creating a potential attack surface where malicious activities within the guest system can impact the host environment through virtual machine instability.
The technical flaw manifests as a divide-by-zero error within the emulated floppy disk controller code, which occurs when specific conditions are met during guest operating system operations. This type of error represents a classic software bug that can be exploited by local users within the guest environment to trigger system crashes. The divide-by-zero condition typically arises when the emulator attempts to perform mathematical operations with zero as a divisor, causing the virtual machine to terminate unexpectedly. The vulnerability's classification as a denial of service issue indicates that the primary impact is system availability rather than data confidentiality or integrity compromise.
From an operational perspective, this vulnerability creates significant risks for virtualization environments where Bochs 2.3 is deployed. Local users within the guest operating system can exploit this flaw to cause virtual machine crashes, effectively denying service to legitimate users of the virtual environment. The impact extends beyond simple disruption as virtual machine crashes can result in data loss, system instability, and potential compromise of the entire virtualization infrastructure. This vulnerability particularly affects environments where multiple virtual machines are running simultaneously, as a single compromised guest can potentially affect other virtual environments sharing the same host resources.
The exploitability of this vulnerability is limited to local users within the guest operating system, which means that external attackers cannot directly leverage this flaw. However, the impact remains significant as it demonstrates the potential for privilege escalation and system compromise within virtualized environments. The vulnerability's presence in Bochs 2.3 highlights the importance of thorough testing and validation of emulated hardware components, particularly those that handle input/output operations. This type of vulnerability aligns with CWE-369, which addresses the divide-by-zero error condition, and represents a common weakness in virtualization software that can be exploited through improper input validation.
Mitigation strategies for this vulnerability involve immediate patching of the Bochs 2.3 software to address the divide-by-zero error in the floppy disk controller implementation. System administrators should also implement monitoring and alerting mechanisms to detect virtual machine crashes that may indicate exploitation attempts. Additional defensive measures include restricting guest operating system privileges, implementing network segmentation to limit potential attack vectors, and maintaining regular backups of virtual machine configurations to enable rapid recovery from exploitation attempts. The vulnerability serves as a reminder of the critical importance of validating all emulated hardware components in virtualization platforms and demonstrates how seemingly minor software flaws can have significant operational impacts. Organizations using Bochs or similar virtualization software should conduct thorough security assessments to identify and remediate similar vulnerabilities in their virtual environments.