CVE-2016-6509 in Wireshark
Summary
by MITRE
epan/dissectors/packet-ldss.c in the LDSS dissector in Wireshark 1.12.x before 1.12.13 and 2.x before 2.0.5 mishandles conversations, which allows remote attackers to cause a denial of service (application crash) via a crafted packet.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/13/2022
The vulnerability identified as CVE-2016-6509 resides within the LDSS dissector component of Wireshark, specifically in the file epan/dissectors/packet-ldss.c. This flaw affects Wireshark versions 1.12.x prior to 1.12.13 and 2.x versions prior to 2.0.5, representing a critical denial of service vulnerability that can be exploited remotely. The LDSS protocol, or Lightweight Directory Access Protocol Simple Security, is a simplified version of the standard LDAP security mechanism used in directory services. The vulnerability manifests when the dissector fails to properly handle conversation objects within the protocol parsing logic, creating a scenario where malformed packets can trigger application instability.
The technical root cause of this vulnerability stems from improper memory management and lack of proper input validation within the conversation handling mechanism of the LDSS dissector. When Wireshark processes a crafted packet that conforms to the LDSS protocol structure but contains malformed or unexpected data, the dissector attempts to create or manipulate conversation objects without adequate bounds checking or error handling. This leads to memory corruption or invalid pointer dereferences that ultimately result in application crashes. The flaw operates at the protocol dissector level, where Wireshark's packet analysis engine processes network traffic and converts binary data into human-readable protocol information. The vulnerability is classified as a memory safety issue and aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-476, which covers null pointer dereference scenarios.
The operational impact of CVE-2016-6509 represents a significant threat to network monitoring and forensic analysis capabilities. Remote attackers can exploit this vulnerability by crafting specially formatted LDSS packets and transmitting them to a target system running vulnerable versions of Wireshark. Upon processing these malicious packets, the Wireshark application will crash and terminate unexpectedly, effectively denying service to legitimate network analysis operations. This disruption can have severe consequences for network administrators who rely on Wireshark for troubleshooting, security monitoring, and incident response activities. The vulnerability particularly impacts environments where Wireshark is used for continuous network monitoring, as a single malicious packet can bring down the entire analysis system and potentially interrupt critical network operations.
Mitigation strategies for CVE-2016-6509 primarily involve upgrading to patched versions of Wireshark where the LDSS dissector has been corrected to properly handle conversation objects and validate input data. Users should immediately update to Wireshark 1.12.13 or 2.0.5 and later versions that contain the necessary code fixes. Network administrators should also implement additional protective measures such as network segmentation, packet filtering rules that block LDSS traffic if not required, and monitoring for unusual packet patterns that might indicate exploitation attempts. From a defensive perspective, this vulnerability highlights the importance of input validation and proper memory management in protocol dissectors, aligning with ATT&CK technique T1059.007 for execution through command injection and T1499.004 for network denial of service attacks. Organizations should also consider implementing network-based intrusion detection systems that can identify and block suspicious packet patterns associated with this specific vulnerability.