CVE-2021-1251: Cisco Security Advisory: Cisco Small Business RV Series Routers Link Layer Discovery Protocol Vulnerabilities

These vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit another vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerabilities.

Details about the vulnerabilities are as follows:

CVE-2021-1309: Cisco Small Business RV Series Routers Link Layer Discovery Protocol Remote Code Execution and Denial of Service Vulnerability

A vulnerability in the LLDP implementation for Cisco Small Business RV Series Routers could allow an unauthenticated, adjacent attacker to execute arbitrary code on an affected device or cause the device to reload.

This vulnerability is due to missing length validation of certain LLDP packet header fields. An attacker could exploit this vulnerability by sending a malicious LLDP packet to the targeted router. A successful exploit could allow the attacker to execute code on the affected router or cause it to reload unexpectedly, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Bug ID(s): CSCvw62392, CSCvw62410, CSCvw62413, and CSCvw62416
CVE ID: CVE-2021-1309
Security Impact Rating (SIR): High
CVSS Base Score: 8.8
CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE-2021-1251: Cisco Small Business RV Series Routers Link Layer Discovery Protocol Memory Leak Denial of Service Vulnerability

A vulnerability in the LLDP implementation for Cisco Small Business RV Series Routers could allow an unauthenticated, adjacent attacker to cause a memory leak on an affected device.

This vulnerability is due to missing length validation of certain LLDP packet header fields. An attacker could exploit this vulnerability by sending a malicious LLDP packet to the targeted router. A successful exploit could cause continuous memory consumption on an affected device and eventually cause it to reload, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Bug ID(s): CSCvw94339, CSCvw94341, CSCvw95016, CSCvw95017, and CSCvy01220
CVE ID: CVE-2021-1251
Security Impact Rating (SIR): High
CVSS Base Score: 7.4
CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVE-2021-1308: Cisco Small Business RV Series Routers Link Layer Discovery Protocol Denial of Service Vulnerability

A vulnerability in the LLDP implementation for Cisco Small Business RV Series Routers could allow an unauthenticated, adjacent attacker to cause an affected router to reload unexpectedly.

This vulnerability is due to missing length validation of certain LLDP packet header fields. An attacker could exploit this vulnerability by sending a malicious LLDP packet to the targeted router. A successful exploit could allow the attacker to cause the affected router to reload unexpectedly, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Bug ID(s): CSCvw62395, CSCvw62411, CSCvw62417, and CSCvw62418
CVE ID: CVE-2021-1308
Security Impact Rating (SIR): High
CVSS Base Score: 7.4
CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Cisco has released free software updates that address the vulnerabilities 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 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

Customers are advised to upgrade to an appropriate fixed firmware release as indicated in the following table(s):

Cisco Small Business RV Series Routers

Fixed Releases

RV132W

1.0.1.15 and later

RV134W

1.0.1.21 and later

RV160, RV160W, RV260, RV260P, and RV260W

1.0.01.03 and later

RV320 and RV325

Refer to End-of-Sale and End-of-Life Announcement for the Cisco RV320 and RV325 Dual Gigabit WAN VPN Router.

RV340, RV340W, RV345, and RV345P

1.0.03.22 and later1

1. The fixed release for CVE-2021-1251 that was listed in the original version of this advisory was found to be incomplete. To fix all vulnerabilities described in this advisory, upgrade to Release 1.0.03.22.

To download the firmware from the Software Center on Cisco.com, do the following:

1. Click Browse all.
2. Choose Routers > Small Business Routers > Small Business RV Series Routers.
3. Choose the appropriate router.
4. Choose Small Business Router Firmware.
5. Choose a release from the left pane of the product page.