-----BEGIN PGP SIGNED MESSAGE-----
AUSCERT External Security Bulletin Redistribution
Cisco ASR 1000 Series Aggregation Services Routers
Data-Plane Processing Denial of Service Vulnerability
8 September 2015
AusCERT Security Bulletin Summary
Product: Cisco ASR 1000 Series Routers
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
CVE Names: CVE-2015-6274
- --------------------------BEGIN INCLUDED TEXT--------------------
Vulnerability Alert Cisco ASR 1000 Series Aggregation Services Routers
Data-Plane Processing Denial of Service Vulnerability
Threat Type: CWE-119: Buffer Errors
IntelliShield ID: 40708
First Published: 2015 August 31 23:19 GMT
Last Published: 2015 August 31 23:19 GMT
Port: Not available
Urgency: Unlikely Use
Credibility: Confirmed C
Severity: Mild Damage
CVSS Base: 5.0
CVSS Version 2.0
CVSS Temporal: 4.8
Version Summary: Cisco ASR 1000 Series Aggregation Services Routers contain a
vulnerability that could allow an unauthenticated, remote attacker to cause a
denial of service condition.
A vulnerability in the Cisco ASR 1000 Series Aggregation Services Routers
could allow an unauthenticated, remote attacker to cause a denial of service
The vulnerability is due to the processing of excessive number of IPv4 packets
that require fragmentation and reassembly. An attacker could exploit ths
vulnerability by sending an excessive number of fragmented packets, causing
high Cisco QuantumFlow Processor (QFP) CPU utilization in the Embedded
Services Processor (ESP).
Cisco has confirmed the vulnerability; however, software updates are not
At the time this alert was first published, Cisco ASR 1000 Series Aggregation
Services Routers version 15.5(3)S was vulnerable. Other releases may also be
To exploit this vulnerability, the attacker must send an excessive number of
fragmented packets to the targeted system, making exploitation more difficult
in environments that restrict access from untrusted sources
Cisco indicates through the CVSS score that functional exploit code exists;
however, the code is not known to be publicly available.
Cisco has released bug ID CSCuv71273 for registered users, which contains
additional details and an up-to-date list of affected product versions.
An unauthenticated, remote attacker could exploit the vulnerabilities to cause
high CPU utilization in the ESP by processing excessive IP packets on an
affected device, which could cause a DoS condition.
The vulnerability is due to the processing of an excessive number of IPv4
packets that require fragmentation and reassembly.
An unauthenticated, remote attacker could exploit the vulnerability by sending
100,000 packets per second or higher fragmented packets to the ASR 1000 Series
router, causing high QFP CPU utilization in the ESP.
Administrators are advised to allow only trusted users to have network access.
Administrators can help protect affected systems from external attacks by
using a solid firewall strategy.
Administrators may consider using IP-based access control lists (ACLs) to
allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
Updates are not available.
The security vulnerability applies to the following combinations of products.
Cisco Cisco ASR 1000 Series 15.5 Base, (3)S
The urgency and severity ratings of this alert are not tailored to individual
users; users may value alerts differently based upon their network
configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED
THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF
GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED
THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION
IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE
TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES
THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
- --------------------------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 email@example.com
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:
Australian Computer Emergency Response Team
The University of Queensland
Internet Email: firstname.lastname@example.org
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-----
-----END PGP SIGNATURE-----