CVE-2016-5350 in Wireshark
Summary
by MITRE
epan/dissectors/packet-dcerpc-spoolss.c in the SPOOLS component in Wireshark 1.12.x before 1.12.12 and 2.x before 2.0.4 mishandles unexpected offsets, which allows remote attackers to cause a denial of service (infinite loop) via a crafted packet.
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Analysis
by VulDB Data Team • 09/13/2022
The vulnerability identified as CVE-2016-5350 represents a critical denial of service flaw within Wireshark's network protocol analysis capabilities, specifically affecting the SPOOLS component responsible for dissecting DCERPC spoolss traffic. This issue manifests in versions of Wireshark spanning 1.12.x prior to 1.12.12 and 2.x versions before 2.0.4, where the packet dissection logic fails to properly handle unexpected offset values in printer spooler protocol communications. The flaw resides in the epan/dissectors/packet-dcerpc-spoolss.c file, which processes Windows printer spooler remote procedure calls that are commonly encountered in enterprise network environments where print services are utilized.
The technical nature of this vulnerability stems from improper input validation within the DCERPC spoolss dissector module. When processing malformed network packets containing unexpected offset values, the dissection routine enters an infinite loop condition that consumes excessive CPU resources and prevents further packet processing. This occurs because the code does not implement proper bounds checking or offset validation before proceeding with the dissecting logic, allowing attackers to craft specially crafted packets that trigger the problematic code path. The vulnerability maps to CWE-129, which describes improper validation of array indices, and more specifically aligns with CWE-691, indicating insufficient control flow management in the face of unexpected input data. From an operational perspective, this flaw presents a significant risk to network monitoring and security analysis operations where Wireshark is deployed as a primary tool for network traffic inspection.
The operational impact of CVE-2016-5350 extends beyond simple service disruption, potentially compromising network security monitoring capabilities and creating opportunities for more sophisticated attacks. An attacker exploiting this vulnerability can cause a denial of service condition that affects the entire Wireshark application, rendering it unable to process subsequent network traffic until manually restarted. This disruption is particularly concerning in enterprise environments where network administrators rely on continuous traffic analysis for security monitoring and incident response activities. The vulnerability also aligns with ATT&CK technique T1499.001, which covers network disruption through denial of service attacks, and demonstrates how protocol analysis tools can themselves become targets for exploitation. The infinite loop condition created by this flaw effectively creates a resource exhaustion scenario that can be leveraged by attackers to disrupt network monitoring operations and potentially mask other malicious activities.
Mitigation strategies for CVE-2016-5350 primarily focus on immediate software updates and deployment of patched versions of Wireshark. Organizations should prioritize upgrading to Wireshark versions 1.12.12 or 2.0.4 and later, which contain the necessary code modifications to properly validate offset values in DCERPC spoolss packets. Network administrators should also consider implementing additional monitoring and alerting mechanisms to detect abnormal CPU usage patterns that might indicate exploitation attempts. The fix typically involves adding proper input validation checks before processing offset values, ensuring that all array indices and memory offsets fall within expected ranges before proceeding with dissection operations. Additionally, organizations may want to consider implementing network segmentation and access controls to limit exposure to potentially malicious traffic, particularly in environments where untrusted network data sources exist. Security teams should also conduct regular vulnerability assessments of network monitoring tools to identify and remediate similar issues that could potentially affect other protocol dissectors within the Wireshark ecosystem.