11 thoughts on - CentOS 6 Fix Sudo CVE-2021-3156

• is that what you expect to find?
  https://access.redhat.com/errata/RHSA-2021:0227

• Hi

  You can use oracle linux 6 , it is still supported (till March 2021)

• But I don’t find this sudo update or the recent openssl update in their repos? Is this for paying customers only or what?

  Simon

• Il 2021-01-27 09:34 Walter H. ha scritto:

  Yes, something similar… Thanks.

• I think it is just not released yet. OL6 is on support track still

• CentOS-6 compatible packages are available from the official sudo webpage. It’s a later version of sudo and I’m not sure if that will cause problems. I’ve tried installing it and so-far so-good.

  https://www.sudo.ws/download.html

  Cheers, Christian.

• Christian Anthon>

  One minor problem – if you have sudo configured to use LDAP (using /etc/sudo-ldap.conf), then upgrading using the sudo.ws RPM will rename /etc/sudo-ldap.conf as /etc/sudo-ldap.conf.rpmsave and stop sudo working with LDAP

  Moving the original /etc/sudo-ldap.conf back fixes this – but it’s a pity the sudo.ws RPM doesn’t provide /etc/sudo-ldap.conf as a config file – which would prevent this happening

  James Pearson

• Maxim Shpakov:

  Looks like Oracle’s el6 sudo update is now available:

  https://yum.oracle.com/repo/OracleLinux/OL6/latest/x86_64/getPackage/sudo-1.8.6p3-29.0.2.el6_10.3.x86_64.rpm https://yum.oracle.com/repo/OracleLinux/OL6/latest/i386/getPackage/sudo-1.8.6p3-29.0.2.el6_10.3.i686.rpm http://oss.oracle.com/ol6/SRPMS-updates/sudo-1.8.6p3-29.0.2.el6_10.3.src.rpm

  * Tue Jan 26 2021 Qing Lin – 1.8.6p3-29.0.2.el6_10.3
  – backport the fix CVE-2021-3156.patch from ol7.

  James Pearson

• I just installed this on a previously fully updated CentOS Linux 6 (x86_64) VM. The package installed fine, the sudo functionality still works but according to the test described in the qualys advisory of running “sudoedit -s /” (without quotes) this system is still vulnerable.

  My CentOS Linux 7 (x86_64), CentOS Linux 8 (x86_64), and CentOS Stream 8 (x86_64) VM running the actual CentOS package do not appear vulnerable running this test.

  Migrating the previously mentioned CentOS Linux 6 vm to Oracle Linux and running the same test shows the fully updated Oracle Linux 6 to be vulnerable as well.

  Has anyone else tried this? Do your results match or differ from mine?

  Thanks, Barry

• Barry Brimer:

  I guess that is a question to ask those that support OL6 ?

  I noticed the same – but I don’t know if running ‘sudoedit -s /’ is an absolute measure of the vulnerability being fixed?

  There is definitely a ‘CVE-2021-3156’ patch that is applied in the SRPM …

  I don’t know of another way of testing if this build fixes the issue ?

  James Pearson

• Il 2021-01-28 19:17 James Pearson ha scritto:

  According to Qualys blog, sudoedit -s ‘\’ `perl -e ‘print “A” x 65536’`
  should core-dump on vulnerable versions.

  I just tried on stock 6.10 and it core-dumps, indeed. Upgrading to the OL6 sudo package fixes the issue, indeed (no more core dump).

  So it seems to work fine to me. Thanks.