PT-2015-4817 · Cisco · Cisco Ios Xr+1

Published 2015-04-15 · Updated 2017-01-06 · CVE-2015-0695

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

AV:N/AC:L/Au:N/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions Cisco IOS XR versions 4.3.4 through 5.3.0

Description The issue is due to improper handling of bridge-group virtual interface (BVI) traffic when certain features are configured, such as Unicast Reverse Path Forwarding (uRPF), policy-based routing (PBR), quality of service (QoS), or access control lists (ACLs). This allows remote attackers to cause a denial of service (chip and card hangs and reloads) by triggering the use of a BVI interface for IPv4 packets. Only Typhoon-based line cards on Cisco ASR 9000 Series Aggregation Services Routers are affected.

Recommendations For Cisco IOS XR versions 4.3.4 through 5.3.0, update to a fixed software version to address the vulnerability. As a temporary workaround, consider disabling the features that trigger the vulnerability, such as uRPF, PBR, QoS, or ACLs, until a patch is available. Restrict access to the BVI interface to minimize the risk of exploitation.

Fix

DoS

Weakness Enumeration

CWE-399

CWE-19

Related Identifiers

CVE-2015-0695

Affected Products

Cisco Asr 9000 Series

Cisco Ios Xr

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2015-0695 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20150415-iosxr · Vendor Advisory
• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20150415-iosxr · Vendor Advisory
• http://securityfocus.com/bid/74162 · Note
• http://securitytracker.com/id/1032139 · Note