In 2022, a significant security vulnerability was discovered in Octopus Server – a popular DevOps automation tool for deploying and operating applications. This bug, tracked as CVE-2022-2782, is both simple and critical: in affected versions, session tokens could remain valid forever. Let’s dive into what happened, how it works, and what you need to do to stay safe.

What’s the Issue?

Normally, when you log in to a web application like Octopus Server, you get a session token. This is a little piece of data your browser hands back to the server, proving you’re you. Session tokens are vital—they let you keep working after login, but should expire after a while to prevent abuse.

However, in some Octopus Server versions, session tokens never expired, due to a flaw in how their validation parameters were checked. This means if an attacker stole or sniffed a valid token, they could access the system… forever.

What Versions Are Vulnerable?

As per Octopus’ official advisory, this issue affects:

What Went Wrong?

The session token parameters—such as expiration (exp), issued-at (iat), and possibly others—weren’t being checked properly. This led to the system believing a session token was valid even after its intended lifespan.

Here’s a simplified illustration (pseudocode)

// Vulnerable code logic (simplified for demonstration)
bool IsTokenValid(Token token) {
    // GOOD: Should check expiration time!
    // BAD: Only checks if token exists and is signed
    return token != null && token.SignatureIsValid;
}

// Should be:
bool IsTokenValid(Token token) {
    return token != null
        && token.SignatureIsValid
        && token.ExpirationTime > DateTime.UtcNow;
}

What’s missing in the first version?
There’s no check if the session is past its expiration date!

Attack Scenario: How Could This Be Exploited?

Let’s say Alice logs into her company’s Octopus Server. She gets a session token. If someone—Bob the attacker—steals this token (through cross-site scripting, a phishing page, or machine compromise), Bob can now access the Octopus Server with Alice’s rights.

But thanks to CVE-2022-2782, Bob can do this not just once, or for an hour, but as long as the vulnerable server runs—weeks, months, maybe years, until the server is fixed. Logging out or resetting the password may not help if the session itself is not invalidated.

Here’s a conceptual exploit (for illustrative purposes only)

import requests

# Assume we have a stolen session token from the "set-cookie" header:
session_token = 'YOUR_STOLEN_SESSION_TOKEN'

# Try accessing a protected resource indefinitely
url = 'https://octopus-server.example.com/api/spaces';
headers = {
    'Cookie': f'session={session_token}'
}

response = requests.get(url, headers=headers)
if response.status_code == 200:
    print("Access granted with stolen session token.")
else:
    print("Access denied.")

With a vulnerable server, this code could work weeks after the token was stolen!

How to Fix and Protect Yourself

1. Update Now:
Upgrade your Octopus Server to version 2022.1.3 or later. This restores correct session expiration.

- Octopus Downloads Page
- Release Notes

2. Invalidate Old Sessions:

Changing critical credentials or rotating secrets.

3. Monitor Logs:
Look for signs of old tokens being reused from unfamiliar machines/IP addresses.

4. Educate Users:
Remind staff not to reuse browsers/machines for sensitive sessions, and watch for phishing.

References and Further Reading

- CVSS Score and NVD Entry
- Octopus Security Advisory (Official)
- Octopus Community Discussion

Summary

CVE-2022-2782 shows how a small oversight—in this case, skipping the expiration check for session tokens—can have massive consequences in real-world security. If you run an affected Octopus Server (2022.1.2 and earlier), update immediately and invalidate old sessions. As always, never underestimate the value of robust, regularly-patched authentication checks in your DevOps stack.

Stay safe, patch often, and keep your session tokens (and secrets) short-lived!

Timeline

Published on: 10/27/2022 10:15:00 UTC
Last modified on: 10/28/2022 19:41:00 UTC