Bug 1816801 (CVE-2020-6581) - CVE-2020-6581 nrpe: insufficient filtering and incorrect parsing of the configuration file may lead to command injection
Summary: CVE-2020-6581 nrpe: insufficient filtering and incorrect parsing of the confi...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2020-6581
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1816804 1816805
Blocks: 1816815
TreeView+ depends on / blocked
 
Reported: 2020-03-24 18:59 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-06-09 17:33 UTC (History)
11 users (show)

Fixed In Version: nrpe 4.0.0
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in nrpe. A command injection is possible due to insufficient filtering. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Clone Of:
Environment:
Last Closed: 2020-03-25 13:16:06 UTC
Embargoed:


Attachments (Terms of Use)

Description Guilherme de Almeida Suckevicz 2020-03-24 18:59:24 UTC
Nagios NRPE 3.2.1 has Insufficient Filtering because, for example, nasty_metachars interprets \n as the character \ and the character n (not as the \n newline sequence). This can cause command injection.

Reference:
https://herolab.usd.de/security-advisories/usd-2020-0002/

Comment 1 Guilherme de Almeida Suckevicz 2020-03-24 19:04:56 UTC
Created nrpe tracking bugs for this issue:

Affects: epel-all [bug 1816805]
Affects: fedora-all [bug 1816804]

Comment 2 Hardik Vyas 2020-03-25 13:16:12 UTC
Statement:

Nagios is considered deprecated. Nagios plugins and Nagios server are no longer maintained or supported. Refer following release notes for details: "https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.5/html-single/3.5_release_notes/index". The older version of nrpe which was shipped with Red Hat Gluster Storage does not support v3 packet format.

Comment 3 Hardik Vyas 2020-03-25 13:16:16 UTC
External References:

https://herolab.usd.de/security-advisories/usd-2020-0002/

Comment 4 Hardik Vyas 2020-03-25 13:16:21 UTC
Mitigation:

Disable nasty_metachars and dont_blame_nrpe option inside the NRPE configuration file - /etc/nagios/nrpe.cfg

Comment 5 Jan ONDREJ 2020-03-25 13:51:46 UTC
(In reply to Hardik Vyas from comment #2)
> Statement:
> 
> Nagios is considered deprecated. Nagios plugins and Nagios server are no
> longer maintained or supported. Refer following release notes for details:
> "https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.5/
> html-single/3.5_release_notes/index". The older version of nrpe which was
> shipped with Red Hat Gluster Storage does not support v3 packet format.

According to this web page, Nagios/NRPE are not supported to monitor Red Hat Gluster Storage 3.5.

Is it supported on any RHEL as monitoring solution? I don't know about any deprecations of Nagios in RHEL. If it's still supported, why this bug has been closed?

Comment 6 Stephen John Smoogen 2020-03-25 14:31:59 UTC
I thought this is the master bug to track the Fedora, Red Hat and EPEL packages bugs. Is this the right one to have closed? One particular to gluster should be closed if it is no longer supported by Red Hat, but I don't think the master should be closed as the Fedora and EPEL parts are still affected.

Comment 7 Hardik Vyas 2020-03-26 10:41:33 UTC
In reply to comment #5:
> (In reply to Hardik Vyas from comment #2)
> > Statement:
> > 
> > Nagios is considered deprecated. Nagios plugins and Nagios server are no
> > longer maintained or supported. Refer following release notes for details:
> > "https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.5/
> > html-single/3.5_release_notes/index". The older version of nrpe which was
> > shipped with Red Hat Gluster Storage does not support v3 packet format.
> 
> According to this web page, Nagios/NRPE are not supported to monitor Red Hat
> Gluster Storage 3.5.
> 
> Is it supported on any RHEL as monitoring solution? I don't know about any
> deprecations of Nagios in RHEL. If it's still supported, why this bug has
> been closed?

This vulnerability is against NRPE package which is only shipped in Red Hat Gluster Storage, non of the other Red Hat offerings include nrpe package hence other Red Hat products are not listed in affected list of products. In Gluster, nrpe is installed as a dependency for gluster-nagios-addons, once all the nagios dependencies are removed from Gluster channel, nrpe will also be removed which is not maintained currently.

Comment 8 Hardik Vyas 2020-03-26 10:56:58 UTC
In reply to comment #6:
> I thought this is the master bug to track the Fedora, Red Hat and EPEL
> packages bugs. Is this the right one to have closed? One particular to
> gluster should be closed if it is no longer supported by Red Hat, but I
> don't think the master should be closed as the Fedora and EPEL parts are
> still affected.

For Fedora and EPEL we generally file separate tracker bugs[1][2], so that the progress can be tracked accordingly. We evaluate master bug closure only based on commercial Red Hat products which are later populated on our CVE page. Community projects like Fedora and EPEL are not populated on CVE page. Hence, if none of our products(non-community) are affected we close the CVE as CLOSED:NOTABUG and status of community projects can be tracked separately on their individual tracker bugs as mentioned below.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1816804
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1816805

Comment 9 Stephen John Smoogen 2020-03-26 14:50:19 UTC
Thank you for the explanation.


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