Cisco IOS XE Software Web Authentication Reflected Cross-Site Scripting Vulnerability

TL;DR 📌

A reflected cross-site scripting (XSS) vulnerability has been identified in the Web Authentication feature of Cisco IOS XE Software. This issue could allow an unauthenticated remote attacker to execute malicious scripts on affected devices. Cisco has released updates to address this vulnerability, but there are no workarounds available.

What happened 🕵️‍♂️

A vulnerability in the Web Authentication feature of Cisco IOS XE Software allows an unauthenticated remote attacker to conduct a reflected cross-site scripting (XSS) attack. This vulnerability arises from improper sanitization of user-supplied input. An attacker could exploit this by persuading a user to click a malicious link, potentially allowing the attacker to steal user cookies from the affected device.

Affected products 🖥️

The vulnerability affects Cisco IOS XE Software when the HTTP or HTTPS features are enabled along with the Web Authentication feature. Specific commands can be used to check if these features are active on your devices.

Fixed software 🔧

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

Workarounds 🧯

There are no workarounds that directly address this vulnerability. However, disabling the HTTP Server feature may eliminate the attack vector. This can be done using the commands no ip http server or no ip http secure-server. Be aware that this may impact other functionalities, such as the Web Management Interface.

Risk in context 🎯

With a CVSS score of 6.1, this vulnerability is rated as Medium severity. The risk is primarily due to the potential for an attacker to exploit the vulnerability through user interaction, as it requires the user to click a malicious link. There is no authentication required for exploitation, making it easier for attackers to target users.

Fast facts ⚡

• Vulnerability Type: Reflected Cross-Site Scripting (XSS)
• CVSS Score: 6.1 (Medium)
• Attack Vector: Remote, unauthenticated
• Exploitation: Proof-of-concept code is available; no known malicious exploitation reported.

For leadership 🧭

This vulnerability poses a Medium risk to your organization, primarily due to the potential for an attacker to execute scripts on affected devices without requiring authentication. The exposure is driven by the need for user interaction, as exploitation requires users to click on malicious links. Immediate action is recommended to patch affected devices within 7 days, as no workarounds are available that fully mitigate the risk.

Operational impact is expected to be minimal, with a brief maintenance window required for updates and no anticipated configuration drift.

Now: Assess affected devices and plan for patching.
Next: Implement patches within 7 days.
Later: Monitor for any signs of exploitation and review security policies related to user interactions.