Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to obtain privileged host OS access, aka XSA-222.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2017-10918 from the MITRE CVE dictionary dictionary and NIST NVD.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 8.5 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Changed |
| Confidentiality | High |
| Integrity Impact | High |
| Availability Impact | High |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 5 | xen | Will not fix |
On x86, specifying "hap_1gb=0 hap_2mb=0" on the hypervisor command
line will avoid the vulnerability.
Alternatively, running all x86 HVM guests in shadow mode will also
avoid this vulnerability. (For example, by specifying "hap=0" in the
xl domain configuration file.)
There is no known mitigation on ARM systems.
Vulmon