CVE-2018-9263 in Wireshark
Summary
by MITRE
In Wireshark 2.4.0 to 2.4.5 and 2.2.0 to 2.2.13, the Kerberos dissector could crash. This was addressed in epan/dissectors/packet-kerberos.c by ensuring a nonzero key length.
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Analysis
by VulDB Data Team • 02/26/2023
The vulnerability identified as CVE-2018-9263 represents a critical denial of service issue within Wireshark's Kerberos protocol dissector that affected multiple versions of the network analysis tool. This flaw specifically impacted Wireshark versions 2.4.0 through 2.4.5 and 2.2.0 through 2.2.13, creating a scenario where legitimate network traffic analysis could be disrupted through carefully crafted malicious packets. The issue stems from insufficient input validation within the Kerberos dissector component, which is responsible for parsing and displaying Kerberos protocol data during network packet analysis operations.
The technical root cause of this vulnerability lies in the packet-kerberos.c file where the dissector fails to properly validate key length parameters during Kerberos protocol parsing. When processing malformed or specially crafted Kerberos packets, the dissector attempts to access memory locations or perform operations based on invalid key length values that could be zero or otherwise inappropriate. This lack of proper boundary checking and input sanitization creates a condition where the dissector crashes or becomes unstable, effectively rendering the network analysis tool unusable for Kerberos traffic inspection. The vulnerability manifests as an improper access to memory or execution of invalid operations when the dissector encounters packets with zero-length keys or malformed key structures.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network security monitoring capabilities. Network security analysts and administrators who rely on Wireshark for Kerberos protocol analysis and troubleshooting could experience complete tool failure when encountering malicious or malformed Kerberos traffic. This crash scenario prevents security professionals from conducting proper network forensics, protocol debugging, or security incident response activities involving Kerberos authentication traffic. The vulnerability is particularly concerning in enterprise environments where Kerberos is commonly used for authentication services, as it could be exploited by attackers to disrupt security monitoring operations or to hide malicious activities within Kerberos traffic streams.
The fix implemented for this vulnerability addresses the core issue by introducing proper validation of key length parameters within the dissector code. The solution ensures that the dissector checks for nonzero key lengths before proceeding with any processing operations, preventing the crash condition that would otherwise occur. This remediation follows established security practices for input validation and defensive programming, aligning with CWE-129 which addresses "Improper Validation of Array Index" and CWE-131 which covers "Incorrect Calculation of Buffer Size." The fix demonstrates proper software engineering practices for preventing buffer overflows and memory access violations that could lead to system instability or potential exploitation.
Organizations should prioritize patching this vulnerability in their Wireshark installations, particularly those monitoring networks that utilize Kerberos authentication services. The remediation process should include updating to Wireshark versions that contain the patched dissector code, which typically corresponds to versions following the affected release series. Security teams should also consider implementing network monitoring procedures to detect unusual Kerberos traffic patterns that might indicate exploitation attempts, although the vulnerability primarily affects the analysis tool rather than the network protocol itself. This vulnerability highlights the importance of maintaining up-to-date network analysis tools and the potential for seemingly benign protocol parsing issues to create significant operational disruptions in security monitoring environments.