Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2020.0802
Cisco IOS XR Software IPsec Packet Processor Denial of
Service Vulnerability
5 March 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco IOS XR Software
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-3190
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-ipsec-dos-q8UPX6m
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco IOS XR Software IPsec Packet Processor Denial of Service Vulnerability
Priority: Medium
Advisory ID: cisco-sa-iosxr-ipsec-dos-q8UPX6m
First Published: 2020 March 4 16:00 GMT
Version 1.0: Final
Workarounds: YesCisco Bug IDs: CSCvr75998
CVE-2020-3190
CWE-400
CVSS Score:
5.8 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L/E:X/RL:X/RC:X
Summary
o A vulnerability in the IPsec packet processor of Cisco IOS XR Software
could allow an unauthenticated remote attacker to cause a denial of service
(DoS) condition for IPsec sessions to an affected device.
The vulnerability is due to improper handling of packets by the IPsec
packet processor. An attacker could exploit this vulnerability by sending
malicious ICMP error messages to an affected device that get punted to the
IPsec packet processor. A successful exploit could allow the attacker to
deplete IPsec memory, resulting in all future IPsec packets to an affected
device being dropped by the device. Manual intervention is required to
recover from this situation.
Cisco has released software updates that address the vulnerability
described in this advisory. There are workarounds that address this
vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-iosxr-ipsec-dos-q8UPX6m
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco IOS XR
Software release prior to 6.4.3, 6.6.3, 7.0.2 and 7.1.1, respectively, that
have the IPsec process ipsec_mp or ipsec_pp running. Both IPsec processes
are running in Cisco IOS XR Software by default.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Determine the Status of the IPsec Processes
Administrators can determine whether IPsec processes are running on a
device by using the show processes | include ipsec command in the device
CLI. The following example shows the output of this command on a device on
which both IPsec processes are running:
RP/0/RP0/CPU0:ios#show processes | include ipsec
Thu Feb 27 13:42:05.618 UTC
222 5460 0K 20 Sleeping ipsec_mp 0
222 6055 0K 20 Sleeping ipsec_mp 0
222 6247 0K 20 Sleeping ipsec_mp 0
222 6258 0K 20 Sleeping ipsec_mp 0
222 6502 0K 20 Sleeping ipsec_mp 0
312 5461 0K 20 Sleeping ipsec_pp 0
312 6044 0K 20 Sleeping ipsec_pp 0
312 6220 0K 20 Sleeping ipsec_pp 0
312 6375 0K 20 Sleeping ipsec_pp 0
312 6824 0K 20 Sleeping ipsec_pp 0
If the command does not return any output, the IPsec processes are not
running and the device is not vulnerable.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect Cisco IOS or
IOS XE Software.
Indicators of Compromise
o When this vulnerability has been exploited successfully, syslog logging
will show messages like the following with a depletion level of 100 percent
or close to 100 percent:
%PKT_INFRA-PAKWATCH-2-DEPLETION_CATASTROPHIC : Depletion level 100 percent for resource PAK FSV
%PKT_INFRA-PAKWATCH-6-USER_INFO : Top 5 users of PAK FSV:
%PKT_INFRA-PAKWATCH-6-INFO_HEAD : PROCESS NAME PID COUNT
%PKT_INFRA-PAKWATCH-6-INFO_BODY : pkg/bin/ipsec_pp 540912 9984
%PKT_INFRA-PAKWATCH-6-INFO_BODY : pkg/bin/udp 540892 16
%PKT_INFRA-PAKWATCH-6-USER_INFO2 : Only 2 users found using PAK FSV.
Manual intervention is required to recover from this failure condition by
restarting the IPsec processes as shown in the following example:
RP/0/RP0/CPU0:ios#process restart ipsec_mp
Fri Feb 21 14:48:58.121 UTC
RP/0/RP0/CPU0:ios#process restart ipsec_pp
Fri Feb 21 14:49:00.973 UTC
Workarounds
o To prevent exploitability of this vulnerability, administrators can apply
access-control lists (ACLs) that deny ICMP unreachable packets to an
affected device.
Customers that do not use any IPsec features can also disable the IPsec
processes as shown in the following example:
RP/0/RP0/CPU0:ios#process shutdown ipsec_mp
Fri Feb 21 14:56:03.870 UTC
Process Shutdown of a process could leave the System in an Inconsistent State. Proceed [confirm]
RP/0/RP0/CPU0:ios#process shutdown ipsec_pp
Fri Feb 21 14:56:09.124 UTC
Process Shutdown of a process could leave the System in an Inconsistent State. Proceed [confirm]
RP/0/RP0/CPU0:ios#
Note: Shutting down the IPsec processes is not persistent across reloads
and would need to be re-applied after every system reload.
Fixed Software
o When considering software upgrades , customers are advised to regularly
consult the advisories for Cisco products, which are available from the
Cisco Security Advisories and Alerts page , to determine exposure and a
complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded
contain sufficient memory and confirm that current hardware and software
configurations will continue to be supported properly by the new release.
If the information is not clear, customers are advised to contact the Cisco
Technical Assistance Center (TAC) or their contracted maintenance
providers.
Fixed Releases
At the time of publication, Cisco IOS XR Software releases 6.4.3 (end of
2020), 6.6.3, 7.0.2, and 7.1.1 and later contained the fix for this
vulnerability. Software maintenance upgrades (SMUs) that fix this
vulnerability were available for Cisco IOS XR Software releases 6.4.2 and
6.5.3 for the ASR9K-PX platform.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Exploitation and Public Announcements
o The Cisco Product Security Incident Response Team (PSIRT) is not aware of
any public announcements or malicious use of the vulnerability that is
described in this advisory.
Source
o This vulnerability was found during the resolution of a Cisco TAC support
case.
Cisco Security Vulnerability Policy
o To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy . This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-iosxr-ipsec-dos-q8UPX6m
Revision History
o +---------+--------------------------+---------+--------+----------------+
| Version | Description | Section | Status | Date |
+---------+--------------------------+---------+--------+----------------+
| 1.0 | Initial public release. | - | Final | 2020-March-04 |
+---------+--------------------------+---------+--------+----------------+
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=IWkM
-----END PGP SIGNATURE-----