CVE-2017-9350 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.6 and 2.0.0 to 2.0.12, the openSAFETY dissector could crash or exhaust system memory. This was addressed in epan/dissectors/packet-opensafety.c by checking for a negative length.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/07/2022
The vulnerability identified as CVE-2017-9350 represents a critical flaw in Wireshark's openSAFETY protocol dissector that affected versions ranging from 2.2.0 through 2.2.6 and 2.0.0 through 2.0.12. This issue falls under the category of denial of service and memory corruption vulnerabilities, specifically targeting the packet analysis capabilities of the widely used network protocol analyzer. The openSAFETY protocol is a safety-critical communication protocol used in industrial automation systems, making this vulnerability particularly concerning for operational technology environments where reliability and stability are paramount.
The technical root cause of this vulnerability stems from inadequate input validation within the packet-opensafety.c dissector component of Wireshark's dissection engine. When processing specially crafted network packets that contain malformed or unexpected data structures, the dissector failed to properly validate the length parameter associated with openSAFETY protocol messages. This lack of validation allowed attackers to craft packets that would cause the dissector to attempt operations with negative length values, leading to unpredictable behavior in the memory management system. The vulnerability specifically manifested when the dissector encountered packet data where the expected length field contained negative values, which would subsequently cause integer underflow conditions during memory allocation or processing operations.
The operational impact of CVE-2017-9350 extends beyond simple service disruption to encompass potential system instability and resource exhaustion scenarios. When exploited, this vulnerability could cause Wireshark to crash entirely, forcing users to restart the application and potentially lose valuable network analysis data. More critically, the vulnerability could lead to memory exhaustion conditions where the application consumes excessive system resources, potentially causing the host system to become unresponsive or forcing other applications to terminate. This behavior aligns with CWE-129, which addresses improper validation of length parameters, and represents a classic example of how insufficient input validation can lead to resource exhaustion and denial of service conditions. The vulnerability also maps to ATT&CK technique T1499.004, which covers network denial of service attacks, as the impact directly affects network analysis capabilities and system availability.
The remediation implemented by the Wireshark development team involved adding explicit validation checks within the epan/dissectors/packet-opensafety.c file to ensure that length parameters are properly validated before being used in memory operations. This fix specifically addressed the negative length condition by introducing bounds checking that prevents the dissector from processing packets with invalid length values. The solution demonstrates proper defensive programming practices that align with industry standards for secure coding, particularly in the context of network protocol analysis tools where malformed data is common. The fix essentially prevents the dissector from entering into problematic code paths when encountering malformed openSAFETY protocol packets, thereby maintaining the stability and reliability of the network analysis environment while preserving the tool's ability to correctly analyze valid network traffic. This remediation approach effectively addresses the underlying security weakness while maintaining backward compatibility with legitimate network analysis operations.