Vulnerability in Xen
CVE-2020-11743
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Xen — versions 4.13.0
- Fedoraproject Fedora — versions 32
Weakness classification (CWE)
References
- xenbits.xen.org/xsa/advisory-316.html (Exploit, Vendor Advisory)
- xenbits.xen.org/xsa/advisory-316.html (Exploit, Vendor Advisory)
- www.openwall.com/lists/oss-security/2020/04/14/3 (mailing-list, Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202005-08 (vendor-advisory)
- www.debian.org/security/2020/dsa-4723 (vendor-advisory)
Frequently asked questions
- What is CVE-2020-11743?
- CVE-2020-11743 is a medium-severity vulnerability in Xen, classified under Improper Handling of Exceptional Conditions. CVSS score: 5.5/10. Published 2020-04-14.
- How severe is CVE-2020-11743?
- Medium severity. CVSS v3 base score is 5.5 out of 10.