CVE-2020-29487 : Vulnerability Insights and Analysis
Discover the impact of CVE-2020-29487, a Xen XAPI vulnerability allowing malicious guests to cause a host denial of service. Learn about affected systems, exploitation, and mitigation steps.
An issue was discovered in Xen XAPI before 2020-12-15. Certain xenstore keys provide feedback from the guest, and are therefore watched by toolstack. This vulnerability can lead to a host denial of service due to unreasonable memory usage in dom0.
Understanding CVE-2020-29487
This CVE identifies a vulnerability in Xen XAPI that allows a malicious guest to cause a denial of service on the host system.
What is CVE-2020-29487?
The vulnerability in Xen XAPI before 2020-12-15 allows a buggy or malicious guest to exploit xenstore keys, leading to excessive memory usage in dom0 and resulting in a denial of service on the host.
The Impact of CVE-2020-29487
The vulnerability can be exploited by a malicious guest to cause unreasonable memory usage in dom0, potentially leading to a denial of service on the host system.
Technical Details of CVE-2020-29487
This section provides detailed technical information about the vulnerability.
Vulnerability Description
- Xen XAPI vulnerability before 2020-12-15
- Watching logic in xenopsd sends one RPC update containing all data, leading to O(N^2) time complexity
- Message-switch retains recent RPC messages, resulting in O(M*N) space complexity
Affected Systems and Versions
- All versions of XAPI are vulnerable
- Systems not using the XAPI toolstack are not affected
Exploitation Mechanism
- Malicious guest exploits xenstore keys
- Excessive memory usage in dom0
- Host denial of service
Mitigation and Prevention
Protecting systems from the CVE-2020-29487 vulnerability is crucial to maintaining security.
Immediate Steps to Take
- Apply patches provided by Xen Project
- Monitor system memory usage for any unusual spikes
- Implement network segmentation to limit guest access
Long-Term Security Practices
- Regularly update and patch Xen XAPI and related components
- Conduct security audits to identify and address vulnerabilities
- Educate users on best practices for system security
Patching and Updates
- Update Xen XAPI to a patched version
- Stay informed about security advisories from Xen Project