Resource management error in Xen - CVE-2020-25603

Vulnerability identifier: #VU46980

CSH Severity: Medium

CVSS v4: 8.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H]

CVE-ID: CVE-2020-25603

CWE-ID: CWE-399

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to event channels control structures can be accessed lockless as long as the port is considered to be valid. Such sequence is missing appropriate memory barrier (e.g smp_*mb()) to prevent both the compiler and CPU to re-order access. A malicious guest may be able to cause a hypervisor crash.

Xen
Gentoo Linux
Opensuse
Ubuntu
Fedora
xen (Alpine package)
xen (Debian package)
libxenevtchn1 (Ubuntu package)
libxengnttab1 (Ubuntu package)
xen-hypervisor-4.11-amd64 (Ubuntu package)
xen-hypervisor-4.11-armhf (Ubuntu package)
libxenmisc4.11 (Ubuntu package)
libxendevicemodel1 (Ubuntu package)
xenstore-utils (Ubuntu package)
xen-utils-4.11 (Ubuntu package)
xen-hypervisor-4.11-arm64 (Ubuntu package)
xen-utils-common (Ubuntu package)
xen
app-emulation/xen
app-emulation/xen-tools

Install updates from vendor's website.

xen (Alpine package) - update to 4.14.0-r1
xen (Debian package) - update to 4.11.4+37-g3263f257ca-1
libxenevtchn1 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
libxengnttab1 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen-hypervisor-4.11-amd64 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen-hypervisor-4.11-armhf (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
libxenmisc4.11 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
libxendevicemodel1 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xenstore-utils (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen-utils-4.11 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen-hypervisor-4.11-arm64 (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen-utils-common (Ubuntu package) - update to 4.11.3+24-g14b62ab3e5-1ubuntu2.3
xen - addressed in versions 4.12.3-5.fc31, 4.13.1-6.fc32, 4.14.0-5.fc33
app-emulation/xen - update to 4.13.2
app-emulation/xen-tools - update to 4.13.2

• https://xenbits.xen.org/xsa/advisory-340.html

• Multiple vulnerabilities in Xen
• Resource management error in xen (Alpine package)
• OpenSUSE Linux update for xen
• Debian update for xen
• Ubuntu update for xen
• Gentoo update for Xen
• Fedora 32 update for xen
• Fedora 31 update for xen
• Fedora 33 update for xen