CentOS Security Advisories OVAL Feed??

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Dear List,

I have spent some time playing around with oscap and the RHEL OVAL feed
(https://www.redhat.com/security/data/oval/v2/RHEL8/, also check Chapter
16 of the RHEL 8 Design Guide). Because I could not find an existing OVAL file for CentOS, I downloaded one of the RHEL8 files and managed to modify (eg. the rhel-8.1-e4s.oval.xml) it to make it work on a CentOS
machine. Basically I just had to change the package signing key check to use the CentOS key and I had to replace the redhat-release RPM package name with “CentOS-release”. Obviously, this would violate all kinds of rights if redistributed, due to the fact that the upstream vendor is named all over the place, but technically it “worked”.

On an internal system running a freshly updated CentOS 8.1 system I
ended up with three errors, titled:

* RHSA-2019:4269: container-tools:rhel8 security and bug fix update
(Important)

* RHSA-2019:3403: container-tools:rhel8 security, bug fix, and enhancement update (Important)

* RHSA-2019:2799: nginx:1.14 security update (Important)

This raises some questions (some of them connected), namely:

Q1) There are no equivalent CESA advisories for those RHSA advisories:
why is that? Note that there are also no equivalent CentOS packages to those mentioned in the RHSA advisories. (My guess: because, when the advisories where issued, CentOS already had moved on to 8.2)

Q2) Does this indicate a problem in the release process / handling of upstream updates on the side of the CentOS project? Were the advisories missed at the time of issuance?

Q3) Does this indicate that only the latest CentOS (minor) release can be considered “secure” or “patched”?

Q4) Is there a native OVAL file released from the CentOS project covering these issues? It could be extremely similar to the RHEL one, but it should take the answers to the above questions into account (eg. it could require the latests minor-release and there would only be one file for CentOS 8 if the answer to Q3 is “yes”).

Q5) If the answer to the last question is “no”: shouldn’t there be such a resource?

Thanks for any answers.

peter

8 thoughts on - CentOS Security Advisories OVAL Feed??

  • I expected just this answer, and we do have a RHEL subscription (and BTW: thanks for the link). But you missed the main point by omitting the other questions (especially Q1, Q2 and Q3): There are upstream package versions that were never rebuilt for CentOS.

    For instance: If, for whatever reason, I am required to stay with nginx
    1.14.1 then the missing rebuild of the packages mentioned in RHSA-2019:2799 (https://access.redhat.com/errata/RHSA-2019:2799) would leave me with a vulnerable system.

    The question for an OVAL feed is actually an add-on question: In the same spirit that is the base for the CentOS project itself: wouldn’t such a feed be a good thing to have? Otherwise your answer could be the catch-all answer to all questions CentOS: Go get a commercial subscription. Personally, I think such an answer is not very helpful.

    So what do you think about the underlying issue? Under what argumentation does it NOT constitute to be an issue?

    peter

  • Modules suck .. :)

    But that is built and in the repo ..

    dnf list ‘nginx*’

    nginx.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-all-modules.noarch
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-filesystem.noarch
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-mod-http-image-filter.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-mod-http-perl.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-mod-http-xslt-filter.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-mod-mail.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream nginx-mod-stream.x86_64
    1:1.14.1-9.module_el8.0.0+184+e34fea82 AppStream

    As I have said before .. mbbox (the item used to build modules) adds an index code (the 184) and a part of the git commit (e34fea82) .. so this will always be different between RHEL and CentOS .. because we use different builders and a different git repo. Red Hat’s RHEL index code is 4108 and the git commit is af250afe

  • The corresponding source RPMs are indeed identical (I checked :-) ), so the packages were (indeed) rebuilt. That was not at all obvious to me.

    OTOH: I probably would have guessed if there had been a corresponding e-mail to CentOS-Announce. At this point, I would like to add that I am extremely impressed by the CentOS project and that I do not want to blame anybody for forgetting such an e-mail (or maybe it was just lost somewhere in SMTP-land) – I just want to state that fact. Thanks for putting in all that hard work!

    With that new knowledge, I also checked my other issues wrt to the container-tools package: Same module issue. So there is a pattern. But there is also the pattern that I cannot find the corresponding CentOS-Announce e-mail. Strange, isn’t it?

    This still leaves me wondering if there should be an attempt at providing a CentOS OVAL file similar to the one by RH that is not generated by taking the upstream file and running some uninspired sed-script on it, like (for reference):

        sed -e ‘s,/etc/redhat-release,/etc/CentOS-release,g’ -e
    ‘s/199e2f91fd431d51/05b555b38483c65d/g’

    However, the question could be asked if such an OVAL file would be of any use, in the light of possibly missing CESA announce e-Mails, because that advisory information must some be translated into the OCAL XML.

    Having said all this: maybe there is some deeper problem here, because of that pattern of missing announce e-mails that correspond with packages that differ in the final version number with respect to the upstream package. Or is this just a coincidence?

    peter

  • We understand that there are no announcements for CentOS 8 .. this (the modules differences) is precisely the reason why (the names do not match up and our scripts require that).

    We do not have the capability to announce these at the present time.

    This is something that needs an engineering solution. Submissions welcome.

  • Thanks for the clarification. This explains exactly what I have seen. Are those scripts available somewhere? A quick search didn’t turn up anything obvious…

    peter

  • Yes. Security errata for previous Enterprise Linux minor releases are a Red Hat product called Extended Update Support (EUS) [0]. CentOS
    doesn’t build EUS updates. CentOS point releases are a point in time reference and an implementation detail, not something you should try to lock your system to. When someone says they are using CentOS X.Y, that just means that they haven’t updated their system since X.Y+1 was released. Effectively, you don’t have CentOS 8.1, you have outdated CentOS 8.

    [0] https://access.redhat.com/articles/rhel-eus