CVE-2018-12893
CVE-2018-12893 is a medium-severity vulnerability in Xen with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v2: 2.1
- EPSS exploit prediction: 0% (33rd percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Xen
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is 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.
- How severe is CVE-2018-12893?
- CVE-2018-12893 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2018-12893 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2018-12893?
- CVE-2018-12893 primarily affects Xen. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2018-12893?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2018-12893 published?
- CVE-2018-12893 was published on 2018-07-02 and last updated on 2026-06-17.
References
- http://www.openwall.com/lists/oss-security/2018/06/27/11
- http://www.securityfocus.com/bid/104572
- http://www.securitytracker.com/id/1041202
- http://xenbits.xen.org/xsa/advisory-265.html
- https://bugzilla.redhat.com/show_bug.cgi?id=1590979
- https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html
- https://security.gentoo.org/glsa/201810-06
- https://support.citrix.com/article/CTX235748
- https://www.debian.org/security/2018/dsa-4236
Affected products (2)
- cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:x86
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
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