A vulnerability in the ingress packet processing functionality of the Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software could allow an unauthenticated, remote attacker to cause both control function (CF) instances on an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient handling of user-supplied data by the affected software. An attacker could exploit this vulnerability by sending malicious traffic to the internal distributed instance (DI) network address on an affected system. A successful exploit could allow the attacker to cause an unhandled error condition on the affected system, which would cause the CF instances to reload and consequently cause the entire VPC to reload, resulting in the disconnection of all subscribers and a DoS condition on the affected system. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180207-vpcdi
[local]VPC-001# show version
Active Software:
Image Version: 19.3.v5
Image Build Number: 65002
Image Description: Deployment_Build
Image Date: Wed Sep 14 05:35:14 EDT 2016
Boot Image: /flash/qvpc-di-19.3.v5.bin
There are no workarounds that address this vulnerability.
Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license: https://www.cisco.com/c/en/us/products/end-user-license-agreement.html
Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.
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.
Customers Without Service Contracts
Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC: https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html
Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.
Fixed Releases
In the following table, the left column lists major releases of Cisco VPC-DI Software and the middle column lists major releases of Cisco StarOS. The right column indicates whether a major release is affected by the vulnerability described in this advisory and the first minor release that includes the fix for this vulnerability.
Customers should upgrade to an appropriate release as indicated in the following table:
| Cisco VPC-DI Major Release |
Cisco StarOS Major Release | Fixed Release for Cisco Bug CSCve17656 |
| N4.0 |
19.2 |
Affected; migrate to N5.1.9 (21.1.v7) |
| N4.2 | 19.3 | Affected; migrate to N5.1.9 (21.1.v7) |
| N4.5 |
20.0 | Affected; migrate to N5.1.9 (21.1.v7) |
| N4.6 | 20.1 |
Affected; migrate to N5.1.9 (21.1.v7) |
| N4.7 | 20.2 | Affected; migrate to N5.1.9 (21.1.v7) |
| N5.0 |
21.0 | Affected; migrate to N5.1.9 (21.1.v7) |
| N5.1 |
21.1 | N5.1.9 (21.1.v7) |
| N5.5 |
21.3 |
N5.5.0 (21.3.v10) |
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.
This vulnerability was found during internal security testing.
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.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.0 | Initial public release. | - | Final | 2018-February-07 |
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