Source: libvirt Version: CVE-2017-1000256/LSN-2017-0002: TLS certificate verification disabled for clients Severity: important Tags: security
Description ----------- The default_tls_x509_verify (and related) parameters in qemu.conf control whether the TLS servers in QEMU request & verify certificates from clients. This works as a simple access control system for QEMU servers by requiring the CA to issue certs to permitted clients. This use of client certificates is disabled by default, since it requires extra work to issue client certificates. Unfortunately the libvirt code was using these configuration parameters when setting up both TLS clients and servers in QEMU. The result was that TLS clients for character devices and disk devices had verification turned off, meaning they would ignore any errors while validating the server certificate. https://www.redhat.com/archives/libvirt-announce/2017-October/msg00001.html -- System Information: Debian Release: buster/sid APT prefers testing APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'stable-updates'), (500, 'oldoldstable'), (500, 'unstable'), (500, 'stable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.13.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system)