CVE-2019-18420
Fixed in a distro release EPSS 3%
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.
Products: xen, debian_linux, fedoraproject fedora
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.9 | xen | 4.11.2-r0 |
| Debian 10 | xen | 4.11.3+24-g14b62ab3e5-1~deb10u1 |
| Debian 12 | xen | 4.11.3+24-g14b62ab3e5-1 |
| Debian 13 | xen | 4.11.3+24-g14b62ab3e5-1 |
| Debian 14 | xen | 4.11.3+24-g14b62ab3e5-1 |
| Debian 9 | xen | 4.8.5.final+shim4.10.4-1+deb9u12 |
| SUSE Enterprise Storage 5 | xen | 4.9.4_06-3.59.1 |
| SUSE HPE Helion OpenStack 8 | xen | 4.9.4_06-3.59.1 |
| SUSE Linux Enterprise Desktop 12 SP4 | xen | 4.11.2_04-2.17.1 |
| SUSE Linux Enterprise Module for Basesystem 15 | xen | 4.10.4_06-3.25.1 |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | xen | 4.12.1_04-3.6.1 |
| SUSE Linux Enterprise Module for Server Applications 15 | xen | 4.10.4_06-3.25.1 |
| SUSE Linux Enterprise Module for Server Applications 15 SP1 | xen | 4.12.1_04-3.6.1 |
| SUSE Linux Enterprise Server 11 SP4-LTSS | xen | 4.4.4_42-61.52.1 |
| SUSE Linux Enterprise Server 12 SP1-LTSS | xen | 4.5.5_28-22.64.1 |
| SUSE Linux Enterprise Server 12 SP2-BCL | xen | 4.7.6_06-43.59.1 |
| SUSE Linux Enterprise Server 12 SP2-LTSS | xen | 4.7.6_06-43.59.1 |
| SUSE Linux Enterprise Server 12 SP3-BCL | xen | 4.9.4_06-3.59.1 |
| SUSE Linux Enterprise Server 12 SP3-LTSS | xen | 4.9.4_06-3.59.1 |
| SUSE Linux Enterprise Server 12 SP4 | xen | 4.11.2_04-2.17.1 |
| SUSE Linux Enterprise Server for SAP Applications 12 SP1 | xen | 4.5.5_28-22.64.1 |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | xen | 4.7.6_06-43.59.1 |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | xen | 4.9.4_06-3.59.1 |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | xen | 4.11.2_04-2.17.1 |
| SUSE Linux Enterprise Software Development Kit 12 SP4 | xen | 4.11.2_04-2.17.1 |
| SUSE OpenStack Cloud 7 | xen | 4.7.6_06-43.59.1 |
| SUSE OpenStack Cloud 8 | xen | 4.9.4_06-3.59.1 |
| SUSE OpenStack Cloud Crowbar 8 | xen | 4.9.4_06-3.59.1 |
| Ubuntu 16.04 LTS | xen | no fix |
| Ubuntu 18.04 LTS | xen | no fix |
| openSUSE Leap 15.0 | xen | 4.10.4_06-lp150.2.25.1 |