CVE-2022-33183 - Stack Buffer Overflow in Brocade Fabric OS CLI (Simple Detailed Guide)

Brocade’s Fabric OS powers a lot of SAN (Storage Area Network) switches. In 2022, security researchers uncovered a dangerous vulnerability—CVE-2022-33183—that lets an authenticated remote attacker crash the system or maybe even run their own malicious code just by abusing common CLI commands, like firmwaredownload and diagshow.

In this post, I’ll walk you through what CVE-2022-33183 is, how it works, with code snippets showing the weakness, links to official advisories, and exclusive, simple explanations. You won’t find this all-in-one anywhere else.

What Is CVE-2022-33183?

It’s a stack buffer overflow bug present in critical administrative commands of Brocade Fabric OS CLI in these versions:

diagshow

These commands are usually run by admins but if an attacker gets valid credentials, even at the lowest remote CLI level, they can trigger the bug.

Breaking Down Buffer Overflows

A buffer overflow happens when software tries to put more data into a block of memory (a "buffer") than it can hold. If the software doesn't check the boundaries, that overflow can overwrite other parts of memory, sometimes allowing an attacker to inject their own code or simply crash the device.

With CVE-2022-33183:
The input passed to firmwaredownload or diagshow commands is not properly checked. If a remote attacker authenticates and sends a massive string as an argument, the string overflows a buffer on the stack.

`

or

Let’s say inside Brocade's firmware, there might be C code like this

#include <stdio.h>
#include <string.h>

void diagshow(char *user_input) {
    char buf[128];
    // BAD: No length check
    strcpy(buf, user_input);
    printf("Diagshow processing: %s\n", buf);
}

If you run

diagshow $(python -c "print('A'*256)")

Now, you’ve written far more than 128 bytes (buf size), overflowing the stack.

Real World Exploit Example

*You need CLI access. Here’s what a real attack might look like:*

# Connect via SSH or telnet with legit (but maybe low-privilege) user creds
ssh admin@10...1

# Issue the command with a huge argument payload
firmwaredownload --host $(python -c "print('A'*300)")

- The device may freeze, reset, or (in theory, depending on architecture & exploit detail) execute injected code.

Official References and Patch Info

- Brocade Advisory: https://docs.broadcom.com/doc/Defect-000600880-CWE-121
- Mitre entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-33183
- NIST NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2022-33183

Update Firmware: Always the first and best line of defense.

2. Limit Access: Restrict SSH/Telnet to trusted IPs only.

Why It Matters

Even though this is an authenticated bug (not just anyone can use it), in big environments, attackers who compromise any low-level credential can knock out or hijack storage switches—big deal for any business.

Summary (TL;DR)

- CVE-2022-33183 lets a logged-in attacker crash or possibly control Brocade SAN switches using very long arguments to CLI commands.

*Patch now!* If your Brocade firmware is out of date, you’re exposed.

- See official advisory here.

Stay safe: Don’t leave your SAN switches wide open!

*Written for admins & engineers who want real answers, not just jargon. Keep your systems sharp—and patched!*

Timeline

Published on: 10/25/2022 21:15:00 UTC
Last modified on: 08/08/2023 14:21:00 UTC