EGI SVG Advisories

Advisory-SVG-CVE-2017-5461

Title:   EGI SVG Advisory [TLP:WHITE] 'HIGH' risk NSS out of bounds write flaw
         CVE-2017-5461 [EGI-SVG-CVE-2017-5461]

Date:    2017-06-06
Updated:

Affected software and risk
==========================

HIGH risk vulnerability concerning NSS out of bounds write flaw

Package : NSS
CVE ID  : CVE-2017-5461

Potentially it is possible to carry out unauthenticated remote code execution,
although it is likely to be difficult to exploit.

Any secure grid service (CE, SE, Argus, FTS, ...) may be affected.


Actions required/recommended
============================

Sites are recommended to update relevant components and restart affected
services if they have not done so already.


Affected software details
=========================

See [R 2], [R 3]


More information
================

See [R 1]

Note that if an exploit were to become available which allows this
vulnerability to be exploited in the EGI environment then the risk will be
elevated to 'Critical'


Component installation information
==================================

Sites running Scientific Linux should see [ R 2]

(Note that this was fixed in Scientific Linux on 20th April 2017, so sites
which have updated since this date and restarted affected services do not need
to take any action.)

Sites running RedHat should see [R 3]

Sites running CentOS should see [R 4]

Some services may need to be re-started.

Where possible it is suggested that sites re-boot after installing the updates.

If this is not possible, Site admins MUST check for ALL services that are still
using the libnss libraries, e.g. using

   needs-restarting

(when available via yum-utils)

or this oneliner:
    grep -l 'libnss.*deleted' /proc/*/maps | tr -cd 0-9\\n | xargs -r ps u



TLP and URL
===========

** WHITE information - Unlimited distribution -
see https://go.egi.eu/tlp for distribution restrictions **

URL:   https://advisories.egi.eu/Advisory-SVG-CVE-2017-5461

Minor updates may be made without re-distribution to the sites


Comments
========

Comments or questions should be sent to svg-rat  at  mailman.egi.eu

If you find or become aware of another vulnerability which is relevant to EGI
you may report it by e-mail to

report-vulnerability at egi.eu

the EGI Software Vulnerability Group will take a look according to the
procedure defined in [R 5]


References
==========

[R 1]  https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-5461

[R 2]  https://www.scientificlinux.org/category/sl-errata/slsa-20171100-1

[R 3]  https://access.redhat.com/security/cve/CVE-2017-5461

[R 4]  http://mirror.centos.org/centos/7/

[R 5]  https://documents.egi.eu/public/ShowDocument?docid=2538

Credit
======

SVG was alerted to this vulnerability by Mischa Salle

Timeline
========
Yyyy-mm-dd  [EGI-SVG-2017-CVE-2017-5641]

2017-05-02 SVG alerted to this vulnerability by Mischa Salle
2017-05-09 Unclear whether exploitable in EGI
2017-06-02 EGI SVG Risk Assessment completed.
2017-06-06 Advisory/Alert sent to sites


Context
=======

This advisory has been prepared as part of the effort to fulfil EGI SVG's
purpose "To minimize the risk to the EGI infrastructure arising from software
vulnerabilities"

The risk is that assessed by the group, according to the EGI SVG issue handling
procedure [R 5]  in the context of how the software is used in the EGI
infrastructure. It is the opinion of the group, we do not guarantee it to be
correct. The risk may also be higher or lower in other deployments depending on
how the software is used.

Others may re-use this information provided they:-

1) Respect the provided TLP classification

2) Credit the EGI https://www.egi.eu/ Software Vulnerability Group


On behalf of the EGI SVG,