CVE-2018-16452 in tcpdump
Summary
by MITRE
The SMB parser in tcpdump before 4.9.3 has stack exhaustion in smbutil.c:smb_fdata() via recursion.
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Analysis
by VulDB Data Team • 12/03/2025
The vulnerability identified as CVE-2018-16452 represents a critical stack exhaustion issue within the tcpdump network packet analysis tool, specifically affecting versions prior to 4.9.3. This flaw exists within the Server Message Block protocol parser implementation, where recursive function calls in the smbutil.c file lead to rapid stack consumption during packet processing. The vulnerability manifests when tcpdump encounters specially crafted SMB packets that trigger the smb_fdata() function to execute recursively, ultimately exhausting the available stack space and causing a denial of service condition.
The technical implementation of this vulnerability resides in the smb_fdata() function within the tcpdump source code, which employs recursive parsing logic to handle SMB packet structures. When processing malformed or crafted SMB traffic, the recursive calls can spiral into deep call stacks that exceed the system's allocated stack memory limits. This recursive behavior is particularly dangerous because SMB protocol packets can contain nested structures that naturally lend themselves to recursive parsing approaches, making the vulnerability exploitable through carefully constructed network traffic that appears legitimate but contains maliciously nested data structures. The flaw falls under the category of stack-based buffer overflow conditions as defined by CWE-129 and CWE-772, representing a specific implementation weakness in recursive algorithm design.
From an operational impact perspective, this vulnerability enables remote attackers to execute denial of service attacks against systems running vulnerable versions of tcpdump, which are commonly deployed in network monitoring and security analysis environments. The attack requires minimal privileges and can be executed through standard network traffic, making it particularly dangerous in production environments where tcpdump is used for network traffic analysis and intrusion detection. Network administrators and security operations centers that rely on tcpdump for monitoring critical network infrastructure become vulnerable to attacks that can disrupt network visibility and monitoring capabilities. The vulnerability directly impacts the availability of network analysis services and can potentially be leveraged as part of broader attack chains that aim to compromise network monitoring systems. According to ATT&CK framework, this vulnerability maps to T1490 - Indicator Removal on Host and T1566 - Phishing, as it can be used to disrupt network monitoring capabilities and potentially enable further attacks by reducing the effectiveness of security monitoring.
The recommended mitigation strategy involves immediate upgrading to tcpdump version 4.9.3 or later, which contains the patched implementation that eliminates the recursive parsing pattern in smb_fdata() function. Organizations should also implement network segmentation and access controls to limit exposure of systems running tcpdump to untrusted network traffic. Additional defensive measures include implementing network-based intrusion detection systems with signature-based detection for known malicious SMB traffic patterns and monitoring for abnormal tcpdump process behavior that might indicate exploitation attempts. Security teams should also consider deploying alternative network analysis tools that do not exhibit similar recursive parsing vulnerabilities and maintain regular patching schedules to ensure all network monitoring tools remain current with security updates. The vulnerability highlights the importance of proper input validation and recursive algorithm design in network security tools, emphasizing the need for defensive programming practices that prevent stack exhaustion conditions.