Summary

• A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to create a file or overwrite any file on the filesystem of an affected device, including system files.

  The vulnerability occurs because there is no validation of parameters when a specific CLI command is used. An attacker could exploit this vulnerability by authenticating to an affected device and using the command at the CLI. A successful exploit could allow the attacker to overwrite any file on the disk of the affected device, including system files. The attacker must have valid administrative credentials on the affected device to exploit this vulnerability.

  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-fxos-arbitrary-file-BLk6YupL

  This advisory is part of the August 2023 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: August 2023 Semiannual Cisco FXOS and NX-OS Software Security Advisory Bundled Publication.

Affected Products

• Vulnerable Products

  At the time of publication, this vulnerability affected the following Cisco products if they were running a vulnerable release of Cisco FXOS Software:

  • Firepower 1000 Series (CSCwd35726, CSCwd05772)
  • Firepower 2100 Series (CSCwd35726, CSCwd05772)
  • Firepower 4100 Series (CSCwb91812, CSCwd35722)
  • Firepower 9300 Security Appliances (CSCwb91812, CSCwd35722)
  • Secure Firewall 3100 Series (CSCwd35726, CSCwd05772)

  For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory.

  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 the following Cisco products:

  • MDS 9000 Series Multilayer Switches
  • Nexus 1000 Virtual Edge for VMware vSphere
  • Nexus 1000V Switch for Microsoft Hyper-V
  • Nexus 1000V Switch for VMware vSphere
  • Nexus 3000 Series Switches
  • Nexus 5500 Platform Switches
  • Nexus 5600 Platform Switches
  • Nexus 6000 Series Switches
  • Nexus 7000 Series Switches
  • Nexus 9000 Series Fabric Switches in ACI mode
  • Nexus 9000 Series Switches in standalone NX-OS mode
  • UCS 6200 Series Fabric Interconnects
  • UCS 6300 Series Fabric Interconnects
  • UCS 6400 Series Fabric Interconnects
  • UCS 6500 Series Fabric Interconnects

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• 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.

  Cisco FXOS Software

  To help customers determine their exposure to vulnerabilities in Cisco FXOS Software, Cisco provides the Cisco Software Checker. This tool identifies any Cisco security advisories that impact a specific software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities that are described in all the advisories that the Software Checker identifies (“Combined First Fixed”).

  To use the tool, go to the Cisco Software Checker page and follow the instructions. Alternatively, use the following form to search for vulnerabilities that affect a specific software release. To use the form, follow these steps:

  1. Choose which advisories the tool will search-only this advisory, only advisories with a Critical or High Security Impact Rating (SIR), or all advisories.
  2. Choose the appropriate platform. Note: Firepower 1000 Series and 2100 Series appliances and Secure Firewall 3100 Series appliances use Cisco FXOS Software as an underlying operating system, which is included in Cisco ASA Software unified image bundles or in Cisco FTD Software unified image bundles. Select either ASA or FTD software to get results for that platform.
  3. Enter a release number-for example, 2.9.1.158 for Cisco Firepower 4100 Series Security Appliances.
  4. Click Check.

  
  

  Only this advisory All Critical and High advisories All advisories Cisco FXOS Software Cisco ASA Software Cisco FTD Software Any Platform Firepower 4100 Series Firepower 9000 Series

Exploitation and Public Announcements

• 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.

Source

• This vulnerability was found during internal security testing.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-arbitrary-file-BLk6YupL

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2023-AUG-23

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