Summary

• A vulnerability in the web-based management interface of certain Cisco Small Business RV Series Routers could allow an authenticated, remote attacker to execute arbitrary commands with root privileges. The attacker must have either a valid credential or an active session token.

  The vulnerability is due to lack of input validation of the HTTP payload. An attacker could exploit this vulnerability by sending a malicious HTTP request to the web-based management interface of the targeted device. A successful exploit could allow the attacker to execute commands with root privileges.

  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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191106-sbrv-cmd-x

Affected Products

• Vulnerable Products

  This vulnerability affects the following Cisco Small Business RV Series Routers if they are running a firmware release earlier than 4.2.3.10:

  • RV016 Multi-WAN VPN Router¹
  • RV042 Dual WAN VPN Router
  • RV042G Dual Gigabit WAN VPN Router
  • RV082 Dual WAN VPN Router¹

  1. The Cisco RV016 Multi-WAN VPN Router and RV082 Dual WAN VPN Router have reached the end of software maintenance.

  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 RV320 and RV325 Dual Gigabit WAN VPN Routers.

Workarounds

• There are no workarounds that address this vulnerability.

  However, administrators can reduce the attack surface by disabling the Remote Management feature if there is no operational requirement to use it. Note that the feature is disabled by default.

  Administrators can disable the Remote Management feature by choosing Firewall > General and unchecking the Remote Management check box. Disabling the feature will disable the web-based management interface on the WAN IP address, which is reachable through the WAN ports. The interface will still be available on the LAN IP address, which is reachable through the LAN ports.

Fixed Software

• 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

  Cisco fixed this vulnerability in firmware releases 4.2.3.10 and later for the Cisco RV042 Dual WAN VPN Router and RV042G Dual Gigabit WAN VPN Router.

  Customers can download the firmware from the Software Center on Cisco.com by doing the following:

  1. Click Browse all.
  2. Choose Routers > Small Business Routers > Small Business RV Series Routers.
  3. Choose a specific product from the right pane of the product selector.
  4. Click Small Business Router Firmware.

Exploitation and Public Announcements

• In June 2022, the Cisco Product Security Incident Response Team (PSIRT) became aware of additional attempted exploitation of this vulnerability in the wild. Cisco continues to strongly recommend that customers upgrade to a fixed software release to remediate this vulnerability.

Source

• Cisco would like to thank security researcher Michel Gaschet--Clousier of Orange Cyberdéfense for reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191106-sbrv-cmd-x

Revision History

• Version	Description	Section	Status	Date
  1.2	Updated exploitation information.	Exploitation and Public Announcements	Final	2022-DEC-15
  1.1	The source was updated to change the credit string.	Source	Final	2019-NOV-06
  1.0	Initial public release.	-	Final	2019-NOV-06

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