Cisco IOS Software Industrial Ethernet Switch Device Manager Denial of Service Vulnerability

TL;DR 📌

A denial of service (DoS) vulnerability has been identified in the web UI of Cisco IOS Software for Industrial Ethernet Switches. An authenticated remote attacker with low privileges can exploit this vulnerability by sending a specially crafted URL, potentially causing the device to reload and become unavailable. Cisco has released software updates to address this issue, but there are no workarounds available.

What happened 🕵️‍♂️

A vulnerability in the web UI of Cisco IOS Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on affected devices. This vulnerability arises from improper input validation, enabling attackers to exploit it by sending a crafted URL in an HTTP request. A successful exploit could lead to the affected device reloading, resulting in a DoS condition.

Affected products 🖥️

The following Cisco Industrial Ethernet (IE) Series Switches are affected if they are running a vulnerable release of Cisco IOS Software and have the HTTP Server feature enabled:

• IE 2000 Series
• IE 3010 Series
• IE 4000 Series
• IE 4010 Series
• IE 5000 Series

To check if the HTTP Server feature is enabled, use the command: show running-config | include ip http server|secure|active.

Fixed software 🔧

Upgrade to the first fixed release in your train (or later):

Workarounds 🧯

There are no workarounds that directly address this vulnerability. However, a mitigation is available: disabling the HTTP Server feature will eliminate the attack vector. This can be done using the commands no ip http server or no ip http secure-server in global configuration mode. Both commands must be executed if both HTTP and HTTPS servers are enabled.

Risk in context 🎯

The vulnerability has a CVSS score of 7.7, indicating a High severity risk. The exposure is primarily driven by the requirement for authentication and the potential for denial of service. There is a risk of operational impact if the HTTP Server feature is disabled, but this is a necessary step until devices can be upgraded.

Fast facts ⚡

• Vulnerability: DoS in Cisco IOS Software web UI
• CVSS Score: 7.7 (High)
• Affected Products: IE 2000, 3010, 4000, 4010, and 5000 Series Switches
• Exploitation: Requires authenticated access
• Mitigation: Disable HTTP Server feature

For leadership 🧭

This vulnerability poses a High risk (CVSS 7.7), primarily affecting devices with the HTTP Server feature enabled. While exploitation requires authenticated access, a successful attack could lead to a denial of service, impacting device availability. Immediate remediation is essential: disable the HTTP Server feature as a temporary measure and plan for software upgrades within 7 days.

• Now: Disable HTTP Server feature to mitigate risk.
• Next: Assess and upgrade to fixed software versions as soon as possible.
• Later: Monitor for any public announcements regarding exploitation.

By addressing this vulnerability promptly, we can minimize the risk of service disruption and maintain operational integrity.