CVE-2021-40120: Cisco Security Advisory: Cisco Small Business RV Series Routers Command Injection Vulnerability

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Summary

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• A vulnerability in the web-based management interface of certain Cisco Small Business RV Series Routers could allow an authenticated, remote attacker with administrative privileges to inject arbitrary commands into the underlying operating system and execute them using root-level privileges.

  This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending malicious input to a specific field in the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system as a user with root-level privileges.

  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-sbrv-cmdinjection-Z5cWFdK

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Affected Products

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• At the time of publication, this vulnerability affected the following Cisco Small Business RV Series Routers if they had the remote management feature enabled:

  • RV016 Multi-WAN VPN Routers
  • RV042 Dual WAN VPN Routers
  • RV042G Dual Gigabit WAN VPN Routers
  • RV082 Dual WAN VPN Routers
  • RV320 Dual Gigabit WAN VPN Routers
  • RV325 Dual Gigabit WAN VPN Routers

  See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

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Workarounds

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• 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.

  While this mitigation has been deployed and was proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions. Customers should be aware that any workaround or mitigation that is implemented may negatively impact the functionality or performance of their network based on intrinsic customer deployment scenarios and limitations. Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment.

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Fixed Software

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• Cisco has not released and will not release software updates to address the vulnerability described in this advisory. The Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 Routers have entered the end-of-life process. Customers are advised to refer to the end-of-life notices for these products:

  • End-of-Sale and End-of-Life Announcement for the Cisco RV016 Multi-WAN VPN Router
  • End-of-Sale and End-of-Life Announcement for the Cisco RV042 and RV042G VPN Router (all models)
  • End-of-Sale and End-of-Life Announcement for the Cisco RV082 Dual WAN VPN Router
  • End-of-Sale and End-of-Life Announcement for the Cisco RV320 and RV325 Dual Gigabit WAN VPN Router

  When considering a device migration, 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 new devices will be sufficient for their network needs; the new devices contain sufficient memory, and current hardware and software configurations will continue to be supported properly by the new product. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

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Exploitation and Public Announcements

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• The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

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Source

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• Cisco would like to thank leetsun for reporting this vulnerability.

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Cisco Security Vulnerability Policy

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• 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.

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URL

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Revision History

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• Version

  Description

  Section

  Status

  Date

  1.0

  Initial public release.

  -

  Final

  2021-NOV-03

  Show Less

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Legal Disclaimer

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