Recently I have been working on oscap-vm — a script that allows SCAP evaluation of virtual machines and virtual machine storage images. In a way it is similar to the other OpenSCAP wrapper utilities — oscap-ssh and oscap-docker. It was merged to OpenSCAP and will be part of 1.2.7 release, so let us introduce it.

oscap-vm mounts the storage of a VM and sets the oscap tool to scan it in offline mode. That means that you can scan a virtual machine from the host without installing OpenSCAP on it — you can perform an agent-less SCAP scan. Root rights are not required, if you are permitted to access and change the VM you are permitted to run oscap-vm on it. The virtual machine storage is mounted read-only, there is no risk of damage to the filesystem. Because of this you cannot automatically remediate a VM using this tool. If you want remediation functionality for virtual machines and containers, please tell us.

Both XCCDF and OVAL evaluation are supported. You can use plain XCCDF files, source datastreams or plain OVAL files.
Let’s go over a few use-cases. I am using a virtual machine called rhel7.2 in the following examples.

Evaluate a running VM

$ oscap-vm domain rhel7.2 xccdf eval --profile xccdf_org.ssgproject.content_profile_stig-rhel7-server-upstream /usr/share/xml/scap/ssg/content/ssg-rhel7-ds.xml 
Mounting guestfs domain 'rhel7.2' to '/tmp/tmp.c69yOdlBNZ'...
Title   Encrypt Partitions
Rule    xccdf_org.ssgproject.content_rule_encrypt_partitions
Ident   CCE-27128-8
Result  notchecked

[snip]

Title   Create Warning Banners for All FTP Users
Rule    xccdf_org.ssgproject.content_rule_ftp_present_banner
Ident   CCE-RHEL7-CCE-TBD
Result  pass

Unmounting '/tmp/tmp.c69yOdlBNZ'...

Evaluate a storage image

$ oscap-vm image /var/lib/libvirt/images/rhel7.2.qcow2 xccdf eval --profile xccdf_org.ssgproject.content_profile_stig-rhel7-server-upstream /usr/share/xml/scap/ssg/content/ssg-rhel7-ds.xml 
Mounting guestfs image '/var/lib/libvirt/images/rhel7.2.qcow2' to '/tmp/tmp.PgfWcB0R4g'...
Title   Encrypt Partitions
Rule    xccdf_org.ssgproject.content_rule_encrypt_partitions
Ident   CCE-27128-8
Result  notchecked

[snip]

Title   Enable SSH Warning Banner
Rule    xccdf_org.ssgproject.content_rule_sshd_enable_warning_banner
Ident   CCE-27314-4
Result  fail

Title   Create Warning Banners for All FTP Users
Rule    xccdf_org.ssgproject.content_rule_ftp_present_banner
Ident   CCE-RHEL7-CCE-TBD
Result  pass

Unmounting '/tmp/tmp.PgfWcB0R4g'...

Check VM for CVE vulnerabilities

$ wget http://www.redhat.com/security/data/oval/Red_Hat_Enterprise_Linux_7.xml
$ oscap-vm domain rhel7.2 oval eval Red_Hat_Enterprise_Linux_7.xml 
Mounting guestfs domain 'rhel7.2' to '/tmp/tmp.NbvfmaKHbZ'...
Definition oval:com.redhat.rhsa:def:20151852: false
Definition oval:com.redhat.rhsa:def:20151840: false
Definition oval:com.redhat.rhsa:def:20151834: false
Definition oval:com.redhat.rhsa:def:20151793: false
[snip]
Definition oval:com.redhat.rhsa:def:20140685: false
Definition oval:com.redhat.rhsa:def:20140684: false
Definition oval:com.redhat.rhsa:def:20140680: false
Definition oval:com.redhat.rhsa:def:20140679: false
Definition oval:com.redhat.rhsa:def:20140678: false
Definition oval:com.redhat.rhsa:def:20140675: false
Evaluation done.
Unmounting '/tmp/tmp.NbvfmaKHbZ'...