CVE-2018-7324 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-sccp.c had an infinite loop that was addressed by using a correct integer data type.
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Analysis
by VulDB Data Team • 02/08/2023
The vulnerability identified as CVE-2018-7324 represents a critical flaw in Wireshark's SCCP protocol dissector that could lead to denial of service conditions. This issue affected specific versions of Wireshark including releases 2.4.0 through 2.4.4 and 2.2.0 through 2.2.12, making it a widespread concern for network analysis tool users who rely on proper protocol decoding capabilities. The flaw was located within the epan/dissectors/packet-sccp.c file, which handles the decoding of Signaling Connection Control Part messages used in telecommunications protocols. This particular dissector is responsible for interpreting SCCP packets that are commonly found in SS7 signaling networks, which form the backbone of global telecommunications infrastructure. The infinite loop condition occurred when processing malformed or specially crafted SCCP packets, causing the Wireshark application to become unresponsive and consume excessive system resources.
The technical root cause of this vulnerability stems from improper handling of integer data types within the SCCP dissector code. Specifically, the implementation used an incorrect integer size or type that led to a condition where loop counters or iteration variables could not properly decrement or increment, resulting in an infinite loop scenario. This type of flaw falls under CWE-835, which specifically addresses the issue of infinite loops in software implementations. The improper integer handling allowed attackers to craft packets that would cause the dissector to enter an endless loop, consuming CPU cycles and potentially leading to system resource exhaustion. This vulnerability was particularly concerning because it could be triggered simply by opening a specially crafted capture file containing malicious SCCP packets, without requiring any network interaction from the victim.
The operational impact of CVE-2018-7324 extends beyond simple application crashes, as it represents a potential vector for denial of service attacks against network monitoring systems. Security professionals and network administrators who use Wireshark for traffic analysis, troubleshooting, and security monitoring could find their tools rendered unusable by maliciously crafted packets. This vulnerability affects the core functionality of Wireshark's protocol analysis capabilities, particularly when analyzing telecommunications traffic that includes SCCP signaling messages. The flaw could be exploited in scenarios where network analysts are processing capture files from potentially compromised networks, or when Wireshark is used in automated monitoring systems that continuously process network traffic. The infinite loop condition would cause the application to hang indefinitely, requiring manual intervention to terminate the process and potentially leading to service disruption in environments where continuous network monitoring is critical. This type of vulnerability aligns with ATT&CK technique T1499.001, which covers network denial of service attacks targeting application availability.
Mitigation strategies for CVE-2018-7324 primarily involve upgrading to patched versions of Wireshark where the integer data type handling has been corrected. The vulnerability was resolved in Wireshark versions 2.2.13 and 2.4.5, which contain the necessary code modifications to properly handle the integer variables within the SCCP dissector. Users should also implement additional security measures such as validating capture files before opening them, particularly when dealing with untrusted network traffic. Network administrators should consider implementing automated monitoring to detect unusual CPU usage patterns that might indicate exploitation attempts. The fix implemented by the Wireshark development team specifically addressed the integer overflow and loop termination conditions, ensuring that the dissector properly handles all valid and invalid SCCP packet structures without entering infinite loops. Organizations should also review their network monitoring procedures to ensure that any automated systems using Wireshark are resilient to such denial of service conditions and have proper resource limits and timeouts configured to prevent complete system impact.