CVE-2017-5856 Explained : Impact and Mitigation
Learn about CVE-2017-5856, a QEMU vulnerability allowing local guest OS users to trigger a denial of service attack by consuming excessive host memory through specific commands.
QEMU, also known as Quick Emulator, is affected by a memory leak vulnerability in the megasas_handle_dcmd function. This flaw allows local guest OS privileged users to launch a denial of service attack by consuming excessive host memory through specific MegaRAID Firmware Interface (MFI) commands.
Understanding CVE-2017-5856
This CVE entry highlights a memory leak vulnerability in QEMU that can be exploited by local guest OS privileged users to trigger a denial of service attack.
What is CVE-2017-5856?
The vulnerability in the megasas_handle_dcmd function in QEMU enables local guest OS privileged users to exhaust host memory by sending MegaRAID Firmware Interface (MFI) commands with a sglist size exceeding 2 Gb.
The Impact of CVE-2017-5856
The vulnerability allows attackers to cause a denial of service by consuming excessive host memory through specific MFI commands.
Technical Details of CVE-2017-5856
QEMU's vulnerability in the megasas_handle_dcmd function poses a risk to system stability and performance.
Vulnerability Description
The flaw in QEMU's megasas_handle_dcmd function leads to a memory leak, enabling a denial of service attack by consuming significant host memory.
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Versions: Not applicable
Exploitation Mechanism
Attackers with local guest OS privileges can exploit this vulnerability by sending MFI commands with a sglist size exceeding 2 Gb, causing a memory leak and denial of service.
Mitigation and Prevention
To address CVE-2017-5856, immediate steps and long-term security practices are crucial.
Immediate Steps to Take
- Apply security updates promptly
- Monitor system resources for unusual memory consumption
- Restrict guest OS privileges to minimize attack surface
Long-Term Security Practices
- Regularly update and patch QEMU and related software
- Implement network segmentation to limit the impact of potential attacks
- Conduct security training for system administrators and users
Patching and Updates
Ensure that the latest security updates and patches for QEMU are applied to mitigate the risk of memory leak vulnerabilities.