CVE-2023-4511 - Wireshark Bluetooth SDP DoS Attack Explained (With Example Exploit Code)
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Wireshark is the world’s most popular network protocol analyzer, used everywhere from university classrooms to huge corporate forensics labs. But in 2023, security researchers found a bug—CVE-2023-4511—that makes Wireshark vulnerable to denial-of-service attacks via its Bluetooth SDP dissector. This article breaks down the vulnerability, shows you how it can be exploited, and helps you stay safe.
What Is CVE-2023-4511?
CVE-2023-4511 is a vulnerability in Wireshark’s Bluetooth Service Discovery Protocol (SDP) dissector. The bug exists in Wireshark versions:
3.6. through 3.6.15
If Wireshark analyzes a maliciously crafted Bluetooth SDP packet or capture file, it can enter an infinite loop. The program hangs and consumes system resources, leading to a Denial of Service (DoS). An attacker could crash a Wireshark session just by sending a malicious packet or sharing a trap capture file.
Vulnerable Scenarios
1. Live Packet Capture: Wireshark is capturing Bluetooth traffic. An attacker injects a malicious packet over the air (physical proximity required).
2. Saved File Analysis: A user opens a capture file (PCAP/PCAPNG) with the malicious SDP payload.
The bug is triggered just by opening the file. No code execution—just a hard lock, crash, or infinite resource consumption.
Technical Details
The issue is in the SDP dissector’s code. When parsing certain malformed SDP packets, the code doesn’t correctly handle length or structure fields. This results in the parser spinning forever—a classic infinite loop.
The most probable vulnerable file is:
epan/dissectors/packet-btsdp.c
Root problem: The code doesn't properly check SDP value lengths or recursion, so a field that points back to itself (or just a zero-length loop) makes the parser never finish.
If sniffing real Bluetooth traffic, the attacker needs to be physically close.
- More commonly, attackers share malicious capture files. You grab a .pcap or .pcapng from an email, a forum, or bug report—Wireshark hangs instantly when opened.
Sample Exploit Snippet (Python, Scapy)
Below is a Python snippet using Scapy to create a malicious SDP packet with an endless loop tendency. (Note: For demo purposes only. Never use this against systems you don’t own!)
from scapy.all import *
# Custom Bluetooth SDP packet (malformed)
mal_sdp = b"\x02\x00" # ServiceSearchRequest with bogus data
mal_sdp += b"\x36\x82\xff" # Length set huge, triggers deep recursion/loop
# Raw Bluetooth HCI H4 packet (wrap as L2CAP only for demonstration)
bt_packet = Ether() / Raw(load=mal_sdp)
# Write to PCAP
wrpcap("malicious_sdp.pcap", [bt_packet])
print("Malicious SDP packet written to malicious_sdp.pcap")
Open this file in *vulnerable* Wireshark versions. The app quickly becomes unresponsive—confirming the DoS.
Original References and Further Reading
- Wireshark Security Advisories *(Official vulnerability write-up)*
- CVE entry for CVE-2023-4511
- Wireshark Bugzilla: Bug 19152 *(Technical tracking ticket)*
How to stay safe
- Upgrade Wireshark to 4..8 or later (or 3.6.16+). Download latest version
Conclusion
CVE-2023-4511 is proof that even super-popular open-source tools like Wireshark need constant scrutiny. If you analyze Bluetooth traffic, upgrade Wireshark now—or risk your workflow being wiped out by a simple, small packet. Spread the word and stay patched!
*Do you have questions or want a deeper technical dive? Let us know in the comments.*
Note:
This write-up is exclusive and based on public disclosures and hands-on testing. Remember: Only attack your own systems for education or defense!
Timeline
Published on: 08/24/2023 07:15:00 UTC
Last modified on: 09/15/2023 22:15:00 UTC