CVE-2017-6469 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.4 and 2.0.0 to 2.0.10, there is an LDSS dissector crash, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-ldss.c by ensuring that memory is allocated for a certain data structure.
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Analysis
by VulDB Data Team • 09/04/2020
The vulnerability identified as CVE-2017-6469 represents a critical denial-of-service flaw within Wireshark's network protocol analysis software. This issue affects versions 2.2.0 through 2.2.4 and 2.0.0 through 2.0.10, where the LDSS dissector component fails to properly handle malformed data structures during packet processing. The flaw manifests as a crash condition that can be triggered either through direct packet injection into the network analysis environment or by opening a specially crafted capture file containing malformed LDSS protocol data. The vulnerability stems from inadequate memory allocation checks within the dissector implementation, specifically in the epan/dissectors/packet-ldss.c source file where the software fails to validate sufficient memory resources before attempting to process LDSS protocol packets.
The technical nature of this vulnerability places it firmly within the category of memory corruption issues, specifically related to improper memory allocation and handling of data structures. According to CWE classification, this corresponds to CWE-129: Improper Validation of Array Index, which occurs when an application fails to validate array indices or memory allocation sizes before processing data. The flaw enables an attacker to craft malicious packets or capture files that cause the Wireshark application to crash, potentially leading to complete application termination and disruption of network monitoring activities. The operational impact extends beyond simple application instability as network analysts relying on Wireshark for troubleshooting and security monitoring could face unexpected service interruptions when processing legitimate traffic that contains malformed LDSS protocol data.
From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1499.002: Endpoint Denial of Service, as it provides a mechanism for causing service disruption through application crashes. The vulnerability is particularly concerning in enterprise environments where Wireshark is commonly used for network traffic analysis, security incident response, and protocol debugging. When exploited, the crash can occur during routine network monitoring operations, potentially masking actual security incidents or preventing analysts from performing critical network diagnostics. The attack surface is broad since the vulnerability can be triggered through multiple vectors including network packet injection and file-based attacks, making it difficult to fully protect against through traditional network segmentation approaches.
The remediation for CVE-2017-6469 required specific code modifications within the LDSS dissector implementation to ensure proper memory allocation validation. The fix involved updating the epan/dissectors/packet-ldss.c file to include comprehensive checks for memory allocation before processing LDSS protocol data structures. This approach addresses the root cause by implementing proper bounds checking and memory validation procedures that prevent the application from attempting to allocate insufficient memory for data structures. Network security teams should prioritize patching affected Wireshark installations to prevent exploitation, as the vulnerability represents a straightforward denial-of-service risk that can be easily leveraged by attackers to disrupt network monitoring operations. The fix demonstrates the importance of proper memory management practices in protocol dissector implementations and serves as a reminder of the critical need for input validation in network analysis tools that process potentially malicious data from network traffic.