This article was originally published on the Red Hat Customer Portal. The information may no longer be current.
A common query seen at Red Hat is "our auditor says our Red Hat machines are vulnerable to CVE-2015-1234, is this true?" or "Why hasn’t Red Hat updated software package foo to version 1.2.3?" In other words, our customers (and their auditors) are not sure whether or not we have fixed a security vulnerability, or if a given package is up to date with respect to security issues. In an effort to help our security-conscious customers, Red Hat make this information available in an easy to consume format.
What’s the deal with CVEs?
Red Hat is committed to the CVE process. To quote our CVE compatibility page:
We believe that giving our users accurate and complete information about security issues is extremely important. By including CVE names when we discuss security issues in our services and products, we can help users cross-reference vulnerabilities so they spend less time investigating and categorizing security events.
Red Hat has a representative on the CVE Editorial Board and declared CVE compatibility in April 2002.
To put it simply: if it’s a security issue and we fix it in an RHSA it gets a CVE. In fact we usually assign CVEs as soon as we determine a security issue exists (additional information on determining what constitutes a security issue can be found on our blog.).
How to tell if you software is fixed?
A CVE can be queried at our public CVE page. Details concerning the vulnerability, the CVSS v2 metrics, and security errata are easily accessible from here.
To verify you system is secure, simply check which version of the package you have installed and if the NVR of your installed package is equal to or higher than the NVR of the package in the RHSA then you’re safe.
What’s an NVR?
The NVR is the Name-Version-Release of the package. The Heartbleed RHSA lists packages such as: openssl-1.0.1e-16.el6_5.7.x86_64.rpm. So from this we see a package name of "openssl" (a hyphen), a version of 1.0.1e (a hyphen) and the release is 16.el6_5.7. Assuming you are running RHEL 6, x86_64, if you have openssl version 1.0.1e release 16.el6_5.7 or later you’re protected from the Heartbleed issue.
Please note, there is an additional field called "epoch", this field actually supersedes the version number (and release), most packages do not have an epoch number, however a larger epoch number means that a package can override a package with a lower epoch. This can be useful, for example, if you need a custom modified version of a package that also exists in RPM repos you are already using. By assigning an epoch number to your package RPM you can override the same version package RPMs from another repo even if they have a higher version number. So be aware, using packages that have the same name and a higher epoch number you will not get security updates unless you specifically create new RPM's with the epoch number and the security update.
But what if there is no CVE page?
As part of our process the CVE pages are automatically created if public entries exist in Bugzilla. CVE information may not be available if the details of the vulnerability have not been released or the issue is still embargoed. We do encourage responsible handling of vulnerabilities and sometimes delay CVE information from being made public.
Also, CVE information will not be created if the software we shipped wasn't vulnerable.
How to tell if your system is vulnerable?
If you have a specific CVE or set of CVEs that you are worried about you can use the yum command to see if your system is vulnerable. Start by installing yum-plugin-security:
sudo yum install yum-plugin-security
Then query the CVE you are interested in, for example on a RHEL 7 system without the OpenSSL update:
[root@localhost ~]# yum updateinfo info --cve CVE-2014-0224 =============================================== Important: openssl security update =============================================== Update ID : RHSA-2014:0679 Release : Type : security Status : final Issued : 2014-06-10 00:00:00 Bugs : 1087195 - CVE-2010-5298 openssl: freelist misuse causing a possible use-after-free : 1093837 - CVE-2014-0198 openssl: SSL_MODE_RELEASE_BUFFERS NULL pointer dereference in do_ssl3_write() : 1103586 - CVE-2014-0224 openssl: SSL/TLS MITM vulnerability : 1103593 - CVE-2014-0221 openssl: DoS when sending invalid DTLS handshake : 1103598 - CVE-2014-0195 openssl: Buffer overflow via DTLS invalid fragment : 1103600 - CVE-2014-3470 openssl: client-side denial of service when using anonymous ECDH CVEs : CVE-2014-0224 : CVE-2014-0221 : CVE-2014-0198 : CVE-2014-0195 : CVE-2010-5298 : CVE-2014-3470 Description : OpenSSL is a toolkit that implements the Secure Sockets Layer
If your system is up to date or the CVE doesn't affect the platform you're on then no information will be returned.
Red Hat Product Security makes available as much information as we can regarding vulnerabilities affecting our customers. This information is available on our customer portal as well as within the software repositories. As you can see it is both easy and quick to determine if your system is up to date on security patches with the provided information and tools.
The following checklist can be used to check if systems or packages are affected by specific security issues:
1) Check if the issue you're concerned about has a CVE and check the Red Hat CVE page:
2) Check to see if your system is up to date for that issue:
sudo yum install yum-plugin-security yum updateinfo info --cve CVE-2014-0224
3) Alternatively you can check the package NVR in the RHSA errata listed in the CVE page (in #1) and compare it to the packages on your system to see if they are the same or greater.
4) If you still have questions please contact Red Hat Support!
About the author
Red Hat is the world’s leading provider of enterprise open source software solutions, using a community-powered approach to deliver reliable and high-performing Linux, hybrid cloud, container, and Kubernetes technologies.