The Ubuntu Security Team produces OVAL files that can be used to help determine how vulnerable a system is.

The OVAL files are available from here. The files are release-specific.

More background on OVAL and OSCAP.

Traditionally, OVAL would be used by downloading it, running a scan and reviewing the generated report. This method certainly has it's place. However, I thought there needed to be a quicker and faster way of getting some specific information. Specifically, I wanted to see if there was anything vulnerable on my system that could be fixed by a package update and I wanted a way to determine if my system was vulnerable to a specific CVE.

In order to accomplish this I needed a reliable way to parse the oscap results XML into something more easily digestable than the default HTML report output. I fumbled around with some grep/awk/perl/python scripts. Finally I stumbled upon the XSLT file that oscap uses to create the HTML report from the XML results. On my system it gets installed as /usr/share/openscap/xsl/oval-results-report.xsl by the libopenscap8 package. I changed it to output text instead of HTML and started stripping away what I did not need. There might be more that can still be removed from the XSLT or other optimizations that can be made... I make know claims of knowing anything about XML or related tools.

• README.md - this file
• text.xsl - modified version of oscap xslt file to output cve list in text format
• cvescan - script to download oval and scan your system

sudo apt-get install -y libopenscap8 xsltproc

./cvescan -? will display complete usage

Below are some examples:

./cvescan # display a list of CVEs affecting this system that can be fixed with package updates ./cvescan -a # display ALL CVEs affecting this system instead of just CVEs with package fixes ./cvescan -c CVE-2019-54321 # output "vulnerable" and exit 1 if vulnerable. Output "not vulnerable" and exit 0 if not vulnerable ./cvescan -c CVE-2019-54321 -s # similar to above but no output, only exit values