CVE-2017-8903 : Security Advisory and Response
Learn about CVE-2017-8903 impacting Xen versions 4.8.x and earlier on 64-bit systems, allowing unauthorized code execution by PV guest OS users. Find mitigation steps and patching recommendations.
Xen versions 4.8.x and earlier on 64-bit systems mishandle page tables following an IRET hypercall, potentially allowing users of PV guest operating systems to execute unauthorized code on the host OS.
Understanding CVE-2017-8903
Xen vulnerability impacting 64-bit platforms.
What is CVE-2017-8903?
Xen through version 4.8.x on 64-bit platforms mishandles page tables after an IRET hypercall, potentially enabling PV guest OS users to execute arbitrary code on the host OS, known as XSA-213.
The Impact of CVE-2017-8903
- Unauthorized code execution on the host OS by users of PV guest operating systems.
Technical Details of CVE-2017-8903
Xen vulnerability details.
Vulnerability Description
Xen versions 4.8.x and earlier on 64-bit systems improperly handle page tables following an IRET hypercall, allowing potential execution of unauthorized code on the host OS.
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Versions: Xen 4.8.x and earlier
Exploitation Mechanism
The vulnerability arises from mishandling page tables after an IRET hypercall on 64-bit platforms, enabling PV guest OS users to execute unauthorized code on the host OS.
Mitigation and Prevention
Steps to address and prevent the CVE-2017-8903 vulnerability.
Immediate Steps to Take
- Apply vendor patches and updates promptly.
- Monitor vendor advisories for security patches.
- Implement least privilege access controls.
Long-Term Security Practices
- Regularly update and patch Xen software.
- Conduct security assessments and audits.
- Employ network segmentation and isolation.
Patching and Updates
- Apply the latest Xen patches and updates to mitigate the vulnerability.