CVE-2018-11355 in Wireshark
Summary
by MITRE
In Wireshark 2.6.0, the RTCP dissector could crash. This was addressed in epan/dissectors/packet-rtcp.c by avoiding a buffer overflow for packet status chunks.
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Analysis
by VulDB Data Team • 03/14/2023
The vulnerability identified as CVE-2018-11355 represents a critical buffer overflow condition within Wireshark's Real-Time Transport Control Protocol (RTCP) dissector implementation. This flaw existed in Wireshark version 2.6.0 and specifically affected the packet-rtcp.c dissector module responsible for analyzing RTCP packets during network traffic capture and analysis. The RTCP protocol operates alongside RTP to provide control information for media streams, making it essential for VoIP and multimedia communications monitoring. When processing malformed or specially crafted RTCP packets, the dissector would attempt to access memory beyond allocated buffer boundaries, leading to unpredictable behavior including application crashes and potential system instability.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The flaw manifested when the RTCP dissector encountered packet status chunks with malformed length fields or excessive data payloads that exceeded expected buffer dimensions. This condition allowed attackers to craft malicious RTCP packets that would trigger memory corruption upon processing, causing the Wireshark application to terminate abruptly. The vulnerability was particularly concerning given Wireshark's widespread use in network security analysis, penetration testing, and forensic investigations where analysts rely on stable packet analysis tools.
The operational impact of CVE-2018-11355 extends beyond simple application crashes to potential disruption of network monitoring activities and security operations. Network security professionals utilizing Wireshark for real-time traffic analysis could experience unexpected tool failures during critical investigations or incident response activities. The vulnerability created a denial-of-service condition that could be exploited in environments where network traffic analysis is continuously monitored, potentially allowing attackers to disrupt legitimate network analysis operations. Additionally, the instability introduced by this flaw could lead to data loss during packet capture sessions or compromise the integrity of network analysis results.
The fix implemented in epan/dissectors/packet-rtcp.c addressed the root cause by adding proper bounds checking and input validation for packet status chunks. This mitigation strategy aligns with ATT&CK technique T1499.004, which covers network disruption attacks, by preventing the exploitation of buffer overflow vulnerabilities that could be used for denial-of-service attacks. The solution involved modifying the dissector to validate packet length fields before attempting to process status chunks, ensuring that memory allocation remained within safe boundaries. This approach follows established secure coding practices recommended by organizations such as the CERT Coordination Center and aligns with industry standards for defensive programming. The patch demonstrated the importance of input validation in network protocol analysis tools and highlighted the need for robust error handling in dissector modules that process potentially malicious network traffic. Organizations utilizing Wireshark should immediately implement this patch to prevent exploitation and maintain the stability of their network monitoring infrastructure.