Summary

• A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an authenticated, remote attacker with low privileges to perform a denial of service (DoS) attack against an affected device.

  This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web-based management interface of an affected device. A successful exploit could allow the attacker to cause the web-based management interface to become unresponsive.

  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-webui-dos-qdc7qx3

Affected Products

• Vulnerable Products

  At the time of publication, this vulnerability affected Cisco IOS XE Software if it had the web-based management interface enabled.

  Note: To enable the web-based management interface, use the ip http server or ip http secure-server command.

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

  Determine the HTTP Server Configuration

  To determine whether the HTTP Server feature is enabled for a device, log in to the device and use the show running-config | include ip http server|secure|active command in the CLI to check for the presence of the ip http server command or the ip http secure-server command in the global configuration. If either command is present, the HTTP Server feature is enabled for the device.

  The following example shows the output of the show running-config | include ip http server|secure|active command for a device that has the HTTP Server feature enabled:

  Router# show running-config | include ip http server|secure|active
  ip http server
  ip http secure-server

  Note: The presence of either command or both commands in the device configuration indicates that the web UI feature is enabled.

  If the ip http server command is present and the configuration also contains ip http active-session-modules none, the vulnerability is not exploitable over HTTP.

  If the ip http secure-server command is present and the configuration also contains ip http secure-active-session-modules none, the vulnerability is not exploitable over HTTPS.

  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:

  • IOS Software
  • IOS XR Software
  • NX-OS Software

Workarounds

• There are no workarounds that address this vulnerability. However, there is a mitigation.

  Disabling the HTTP Server feature eliminates the attack vector for these vulnerabilities and may be a suitable mitigation until affected devices can be upgraded. To disable the HTTP Server feature, use the no ip http server or no ip http secure-server command in global configuration mode. If both the HTTP server and HTTPS server are in use, both commands are required to disable the HTTP Server feature.

  Allowing only trusted networks to access the HTTP server will limit exposure to these vulnerabilities. The following example shows how to allow remote access to the HTTP server from the trusted 192.168.10.0/24 network:

  !
  ip http access-class ipv4 restrict_ipv4_webui
  !
  ip access-list standard restrict_ipv4_webui 
  permit 192.168.10.0 0.0.0.255
  !

  For additional information, see Filter Traffic Destined to Cisco IOS XE Devices WebUI Using an Access List.

  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.

Fixed Software

• Cisco considers any workarounds and mitigations (if applicable) to be temporary solutions until an upgrade to a fixed software release is available. To fully remediate this vulnerability and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.

  Cisco IOS XE Software

  To help customers determine their exposure to vulnerabilities in Cisco IOS XE 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 determine whether a release is affected by any Cisco Security Advisory. 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. Enter a release number—for example, 15.9(3)M2 or 17.3.3.
  3. Click Check.

   

  Only this advisory All Critical and High advisories All advisories

   

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

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

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-dos-qdc7qx3

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	—	Final	2026-AUG-05

  Show Less

---