What it is about

Prozessoren sind die zentralen Rechenwerke eines Computers. Xen ist ein Virtueller-Maschinen-Monitor (VMM), der Hardware (x86, IA-64, PowerPC) für die darauf laufenden Systeme (Domains) paravirtualisiert. Ein lokaler Angreifer kann eine Schwachstelle in AMD Prozessoren und Xen ausnutzen, um Informationen offenzulegen.

Under what conditions?

Only with access to the device or an account on it. Often the second step after a phishing email.

What can happen in the worst case

An attacker could use the vulnerability to

• Informationen offenzulegen

Am I affected?

Affected according to the BSI:

• Debian Linux
• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• AMD Prozessor EPYC 7001 Series
• AMD Prozessor EPYC Embedded 3000 Series
• AMD Prozessor Athlon 3000 Series
• AMD Prozessor Ryzen 3000 Series
• AMD Prozessor Ryzen PRO 3000 Series
• Open Source Xen <xsa488.patch
• Open Source Xen <xsa488-4.17.patch
• Open Source Xen <xsa488-4.18.patch

and 1 more

The installed version is usually shown under “Help → About” or in the device’s admin interface.

What helps?

Update to at least:

• Open Source Xen xsa488.patch
• Open Source Xen xsa488-4.17.patch
• Open Source Xen xsa488-4.18.patch
• Open Source Xen xsa488-4.20.patch

Is the vulnerability already being exploited?

None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.