CVE-2017-9351 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.6 and 2.0.0 to 2.0.12, the DHCP dissector could read past the end of a buffer. This was addressed in epan/dissectors/packet-bootp.c by extracting the Vendor Class Identifier more carefully.
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Analysis
by VulDB Data Team • 12/07/2022
The vulnerability identified as CVE-2017-9351 represents a critical buffer over-read flaw within the Wireshark network protocol analyzer software. This issue affects versions 2.2.0 through 2.2.6 and 2.0.0 through 2.0.12, where the DHCP dissector component fails to properly validate buffer boundaries during packet analysis. The flaw occurs when processing DHCP packets containing Vendor Class Identifier information, creating a scenario where the software attempts to read memory locations beyond the allocated buffer space. This type of vulnerability falls under the category of memory safety issues commonly classified as CWE-125, which specifically addresses "Out-of-bounds Read" conditions in software implementations.
The technical implementation of this vulnerability stems from inadequate input validation within the packet-bootp.c file, which is responsible for dissecting BOOTP and DHCP protocols. When Wireshark processes DHCP packets with malformed Vendor Class Identifier fields, the dissector routine does not properly check array bounds before accessing memory locations. This allows an attacker to craft specially crafted DHCP packets that, when analyzed by the vulnerable Wireshark version, trigger memory access violations. The operational impact extends beyond simple application crashes, as this vulnerability could potentially be exploited to execute arbitrary code or cause denial of service conditions, particularly in environments where network traffic analysis is performed automatically.
From an operational security perspective, this vulnerability poses significant risks to network monitoring and forensic analysis operations. Network administrators who rely on Wireshark for traffic inspection and security monitoring could find their systems compromised if malicious actors craft DHCP packets designed to exploit this buffer over-read condition. The ATT&CK framework categorizes this type of vulnerability under T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1071.004 for "Application Layer Protocol: DNS" when considering potential exploitation vectors, though the direct attack surface primarily involves network protocol analysis tools. The vulnerability's exploitation requires the attacker to have network access and the ability to inject malicious DHCP traffic into the network segment being monitored.
Mitigation strategies for CVE-2017-9351 focus on immediate software updates to patched versions of Wireshark, which address the buffer over-read condition by implementing proper boundary checks in the Vendor Class Identifier extraction process. Organizations should also consider network segmentation and access controls to limit exposure, while implementing additional monitoring for anomalous DHCP traffic patterns. The fix implemented in epan/dissectors/packet-bootp.c specifically addresses the root cause by ensuring that buffer boundaries are respected during Vendor Class Identifier parsing, preventing the over-read condition that could lead to system instability or potential code execution. Security teams should prioritize patching this vulnerability as part of their regular maintenance procedures, particularly in environments where network traffic analysis is critical for security operations and incident response capabilities.