CVE-2018-7322 in Wireshark
Summary
by MITRE
In Wireshark 2.4.0 to 2.4.4 and 2.2.0 to 2.2.12, epan/dissectors/packet-dcm.c had an infinite loop that was addressed by checking for integer wraparound.
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Analysis
by VulDB Data Team • 02/08/2023
The vulnerability identified as CVE-2018-7322 represents a critical flaw in Wireshark's packet dissection functionality that could lead to denial of service conditions. This issue affected multiple versions of Wireshark including 2.4.0 through 2.4.4 and 2.2.0 through 2.2.12, making it a widespread concern across the network analysis tool's user base. The flaw was located within the DCM dissector component which is responsible for dissecting Data Communication Manager protocol packets used in telecommunications networks. The vulnerability specifically manifested in the epan/dissectors/packet-dcm.c file where a logical error in the dissection logic created a condition that could cause the application to enter an infinite loop during packet processing. This type of vulnerability falls under CWE-835, which describes the weakness of an infinite loop or infinite recursion, making it particularly dangerous as it could be exploited to consume system resources and potentially crash the application.
The technical implementation of this vulnerability stemmed from inadequate input validation and boundary checking within the DCM dissector's parsing logic. When processing specially crafted packets that contained malformed data structures, the dissector would encounter a condition where integer variables would wrap around during arithmetic operations, causing the loop condition to never be satisfied. This integer wraparound behavior resulted in the dissection process becoming trapped in an endless iteration cycle that could only be terminated by manual intervention or system restart. The flaw was particularly insidious because it required no special privileges to exploit, making it accessible to any attacker who could craft malicious network traffic and deliver it to a victim running the vulnerable Wireshark version. The vulnerability aligns with ATT&CK technique T1499.001 which involves network denial of service attacks, and more specifically with T1059.007 related to command and scripting interpreter usage for exploitation.
The operational impact of CVE-2018-7322 was significant for organizations relying on Wireshark for network monitoring and analysis. Network administrators and security professionals who used Wireshark to analyze network traffic would face potential system crashes or unresponsiveness whenever encountering packets that triggered the infinite loop condition. This vulnerability could be exploited in various scenarios including network forensics analysis, security incident response, and routine network monitoring activities. The impact extended beyond simple application crashes as it could disrupt critical network analysis workflows, potentially masking real security incidents or preventing timely response to actual threats. Organizations using Wireshark for intrusion detection or network traffic analysis were particularly vulnerable since these systems often process large volumes of network data automatically without human intervention, increasing the likelihood of encountering malicious packets that would trigger the vulnerability. The flaw also had implications for automated network monitoring systems that rely on Wireshark's dissectors to process network traffic in real-time, potentially causing cascading failures in network security infrastructure.
Mitigation strategies for this vulnerability primarily focused on immediate version upgrades to patched releases of Wireshark. Users were strongly advised to upgrade to Wireshark version 2.4.5 or 2.2.13, which contained the necessary fixes to address the integer wraparound condition in the DCM dissector. The patch implemented by the Wireshark development team included proper boundary checks and validation of integer values during the dissection process to prevent the wraparound condition from occurring. Additionally, network administrators were recommended to implement network segmentation and traffic filtering to limit exposure to potentially malicious packets, though this was considered a temporary workaround rather than a permanent solution. The vulnerability highlighted the importance of input validation and proper boundary checking in network protocol parsing code, emphasizing the need for robust error handling in security tools that process untrusted network data. Organizations were also encouraged to implement monitoring and alerting systems to detect unusual application behavior that might indicate exploitation attempts, and to maintain regular patching schedules for all network analysis and security tools to prevent similar vulnerabilities from being exploited in the future.