Vulnerability in Xen
CVE-2018-12893
An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Xen
- Debian Linux — versions 9.0
References
- www.openwall.com/lists/oss-security/2018/06/27/11 (mailing-list, Patch, Mailing List, Third Party Advisory, Mitigation)
- www.debian.org/security/2018/dsa-4236 (vendor-advisory, Third Party Advisory)
- support.citrix.com/article/CTX235748 (Vendor Advisory)
- security.gentoo.org/glsa/201810-06 (vendor-advisory)
- lists.debian.org/debian-lts-announce/2018/11/msg00013.html (mailing-list)
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Mitigation, Issue Tracking)
- xenbits.xen.org/xsa/advisory-265.html (Patch, Mitigation, Vendor Advisory)
- www.securityfocus.com/bid/104572 (VDB Entry, Third Party Advisory, vdb-entry)
- www.securitytracker.com/id/1041202 (VDB Entry, Third Party Advisory, vdb-entry)
Frequently asked questions
- What is CVE-2018-12893?
- CVE-2018-12893 is a medium-severity vulnerability in Xen. CVSS score: 6.5/10. Published 2018-07-02.
- How severe is CVE-2018-12893?
- Medium severity. CVSS v3 base score is 6.5 out of 10.