CVE Vulnerability

CVE-2019-18420

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen versions 4.6 and newer are vulnerable. Xen versions 4.5 and earlier are not vulnerable. Only x86 PV guests can exploit the vulnerability. HVM and PVH guests, and guests on ARM systems, cannot exploit the vulnerability.

6.3 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 6.8 / Impact : 6.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact COMPLETE

Scope

6.5 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
http://xenbits.xen.org/xsa/advisory-296.html Patch Vendor Advisory
http://www.openwall.com/lists/oss-security/2019/10/31/1 Mailing List Patch
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html Broken Link Mailing List
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/ Mailing List Third Party Advisory
https://www.debian.org/security/2020/dsa-4602 Third Party Advisory
https://seclists.org/bugtraq/2020/Jan/21 Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202003-56 Third Party Advisory
Configurations

Configuration 1

cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
Information

Published : 2019-10-31 02:15

Updated : 2023-02-23 02:33

NVD link : CVE-2019-18420

Mitre link : CVE-2019-18420

Products Affected
No products.
CWE
CWE-134

Use of Externally-Controlled Format String