CVE-2023-4511 - BT SDP Dissector Infinite Loop in Wireshark 4.. to 4..7 and 3.6. to 3.6.15 Results in Denial of Service in Packet Injection or Crafted Capture Files

A critical vulnerability (CVE-2023-4511) has been discovered in the widely used Wireshark network protocol analyzer, specifically affecting versions 4.. to 4..7 and 3.6. to 3.6.15. Exploitation of this vulnerability can result in a denial of service (DoS) attack by causing an infinite loop in the BT SDP dissector.

Wireshark is a popular open-source software for network protocol analysis and troubleshooting. Many network administrators, security researchers, and developers rely on Wireshark to monitor network traffic, identify vulnerabilities, and resolve network-related issues.

In this CVE-2023-4511 long read post, we'll discuss the vulnerability details, examine a code snippet, provide links to original references, and talk about the implications of successful exploitation.

Vulnerability Details

The BT SDP (Bluetooth Service Discovery Protocol) dissector within Wireshark is responsible for breaking down captured Bluetooth packets to enable detailed inspection and analysis. The infinite loop vulnerability results from the improper handling of specific packets, leading to a seemingly endless examination of particular data patterns.

Wireshark 3.6. to 3.6.15

Exploitation of this vulnerability can be triggered by injecting malicious packets into the user's system or by opening a specially crafted capture file containing the harmful packets. This leads to a denial of service (DoS) as the Wireshark application enters an infinite loop, causing the system to become unresponsive and potentially crash.

Code Snippet

A simplified code snippet highlighting the infinite loop vulnerability in Wireshark's BT SDP dissector looks like this:

while (offset < length) {
    entry = tvb_get_guint8(tvb, offset);
    type = entry & TYPE_MASK;
    size = entry & SIZE_MASK;
    
    switch (type) {
    case TYPE_A:
        switch (size) {
        case SIZE_8BIT:
            /* ... */
            break;
        case SIZE_16BIT:
            /* ... */
            break;
        default:
            break;
        }
    case TYPE_B:
        /* ... */
        break;
    default:
        break;
    }

    /* Issue: Infinite loop vulnerability - 'offset' is never incremented */
}

In the above code, the 'offset' variable is never incremented within the loop, which leads to an infinite loop. Properly handling the 'offset' variable ensures that the loop can terminate after processing all relevant data.

Original References

Here are the original references and sources for further reading on CVE-2023-4511 and the Wireshark vulnerability:

1. Wireshark's official advisory regarding the vulnerability

2. NIST National Vulnerability Database (NVD) entry

3. Wireshark Bugzilla tracking the issue

Implications of Successful Exploitation

If an attacker successfully exploits this vulnerability, they can cause a denial of service (DoS) within the affected Wireshark application. Users may experience their systems becoming unresponsive, or even crashing if the attack persists.

Mitigation

To mitigate the risk of this vulnerability, it is recommended that users upgrade Wireshark to the latest version. The Wireshark developers have released updates to address the issue:

Conclusion

It is essential for users of Wireshark to stay informed and up-to-date on software updates and vulnerability disclosures. Users should regularly check the Wireshark website and other relevant sources for new security advisories and update their installations accordingly. Stay safe and stay informed!

Timeline

Published on: 08/24/2023 07:15:00 UTC
Last modified on: 09/15/2023 22:15:00 UTC