081267dc43
This is an automated DistroBaker update from upstream sources. If you do not know what this is about or would like to opt out, contact the OSCI team. Source: https://src.fedoraproject.org/rpms/tog-pegasus.git#6e556193473e062db027bdb29c0ffc2cbfb5e7c4
85 lines
4.1 KiB
Plaintext
85 lines
4.1 KiB
Plaintext
Red Hat Security Enhancements for tog-pegasus
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Access to the Pegasus services:
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
By default, with the configuration as shipped, the upstream Open Group Pegasus
|
|
release allowed any user with an account on the machine (including root) to
|
|
use the network HTTPS port 5989 (by default) and HTTP port 5988 services.
|
|
On authentication failures, though there was the standard PAM authentication
|
|
failure delay, no messages were logged to syslog. This meant that potentially
|
|
a long-running cracker process could try millions of root passwords over the
|
|
network and could possibly discover the root password . If users were unwise
|
|
enough to enable the HTTP service on port 5988, then root passwords could be
|
|
sent unencrypted over the network.
|
|
|
|
This situation was deemed unacceptable by Red Hat RHEL QA test and Security
|
|
Response team engineers.
|
|
|
|
So for the Red Hat tog-pegasus release, PAM access control was enabled, to
|
|
remove these vulnerabilities. There is now a "pegasus" user created during
|
|
install, and users are recommended to use only that user to invoke CIM
|
|
operations over the network.
|
|
|
|
By default:
|
|
|
|
o root password authentication for CIM operations invoked over the network
|
|
HTTPS/HTTP services is denied - the root user is unable to invoke pegasus
|
|
services over the network - only the "pegasus" user may do so.
|
|
|
|
o the root user may invoke CIM operations over the HTTPS/HTTP ports on the
|
|
local machine.
|
|
|
|
o any user other than "pegasus" or "root" may not invoke pegasus services
|
|
over the HTTPS/HTTP ports at all.
|
|
|
|
o any PAM authentication failure will be logged to syslog
|
|
|
|
NOTE: after installation, you must set the password for the pegasus user -
|
|
issue this command as root :
|
|
# passwd pegasus
|
|
- to enable CIM operation network service, if the pegasus user is
|
|
a local system user.
|
|
|
|
Note also that even though a non-root user's password is used to authenticate
|
|
with the cimserver, the cimserver and all CIM Operation Providers run as root.
|
|
This was another reason to restrict use of CIM Operations to only one user.
|
|
|
|
The "pegasus" user may of course be a NIS, Kerberos, or LDAP user, which
|
|
could be used as configured in /etc/nsswitch.conf or with the PAM stack.
|
|
|
|
You may configure this differently, and at your own risk, by modifying the
|
|
pam_access configuration file /etc/Pegasus/access.conf, or by removing the
|
|
line:
|
|
account required pam_access.so accessfile=/etc/Pegasus/access.conf
|
|
from /etc/pam.d/wbem - then tog-pegasus' authentication behaviour would
|
|
be the same as that of the upstream release.
|
|
|
|
SELinux
|
|
~~~~~~~
|
|
There is an SELinux policy for tog-pegasus shipped in selinux-policy-targeted-1.17.30-2.110+ .
|
|
When SELinux is enabled in enforcing mode, the cimserver and providers are restricted to the
|
|
operations allowed to the 'pegasus_t' security context. Also only the pegasus_exec_t context
|
|
may modify the repository, and only the pegasus_exec_conf_t context may modify the pegasus
|
|
configuration files which are of pegasus_conf_t file context.
|
|
|
|
It is also possible to have separate SELinux policy for each provider. Create wrapper
|
|
in '/usr/libexec/pegasus' with its own specific SELinux label for each confined provider.
|
|
The wrapper file name has to be in specific format '$MODULE-cimprovagt' (where $MODULE is
|
|
value of PG_ProviderModule.ModuleGroupName as set during registration of the provider).
|
|
|
|
Original Pegasus's cimprovagt binary was moved to '/usr/libexec/pegasus/cimprovagt',
|
|
'/usr/sbin/cimprovagt' is simple shell script now, which passes all arguments to provider specific
|
|
wrapper if it exists or directly to original cimprovagt in other cases.
|
|
|
|
See example wrapper for Operating System Provider from sblim-cmpi-base package (which instruments
|
|
Linux_OperatingSystem class):
|
|
cmpiOSBase_OperatingSystemProvider-cimprovagt.example
|
|
|
|
ExecShield
|
|
~~~~~~~~~~
|
|
All tog-pegasus binary executables are compiled with ExecShield enabled, which make it nearly
|
|
impossible to modify them or to poke executable code into them.
|
|
|