PT-2019-4885 · Xen+1 · Xen+1
Julian Grall
·
Published
2019-10-31
·
Updated
2023-03-29
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CVE-2019-18423
CVSS v3.1
8.8
High
| Vector | AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Xen versions prior to 4.13
Description
An issue in Xen allows ARM guest OS users to cause a denial of service via a XENMEM add to physmap hypercall. The functions
p2m resolve translation fault() and p2m get entry() use p2m->max mapped gfn to sanity check guest physical frames, but the function p2m get root pointer() ignores unused top bits of a guest physical frame, leading to aliasing. This can cause p2m->max mapped gfn to be updated incorrectly, potentially leading to a hypervisor crash. A malicious guest administrator may exploit this issue to cause a Denial of Service (DoS). Only Arm systems are vulnerable, while x86 systems are not affected.Recommendations
For Xen versions prior to 4.13, update to a newer version to mitigate the risk of exploitation. As a temporary workaround, consider restricting access to the
XENMEM add to physmap hypercall to minimize the risk of exploitation. Additionally, restrict access to the p2m get root pointer() function until a patch is available.Fix
DoS
RCE
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Related Identifiers
Affected Products
Suse
Xen