CVE-2016-7922 in macOS
Summary
by MITRE
The AH parser in tcpdump before 4.9.0 has a buffer overflow in print-ah.c:ah_print().
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7922 represents a critical buffer overflow flaw within the Authentication Header (AH) parser of tcpdump software versions prior to 4.9.0. This issue resides specifically in the print-ah.c source file where the ah_print() function fails to properly validate input data lengths before processing Authentication Header packets. The flaw manifests when tcpdump encounters malformed or oversized AH packets during network traffic analysis, creating a condition where attacker-controlled data can overwrite adjacent memory regions beyond the allocated buffer boundaries. This vulnerability directly impacts the integrity and stability of network analysis tools deployed in security monitoring and incident response environments where tcpdump serves as a fundamental packet inspection utility.
The technical implementation of this buffer overflow stems from inadequate bounds checking within the AH packet parsing logic. When tcpdump processes Authentication Header packets, it attempts to parse the security parameters and authentication data without sufficient validation of the incoming packet structure. The ah_print() function allocates a fixed-size buffer to store parsed AH data but does not verify that the incoming packet data conforms to expected size limitations. This allows an attacker to craft malicious AH packets with oversized authentication fields that exceed the allocated buffer capacity, resulting in memory corruption that can lead to arbitrary code execution or application crashes. The vulnerability is classified as a classic stack-based buffer overflow with direct implications for software reliability and security.
The operational impact of this vulnerability extends beyond simple denial-of-service scenarios to encompass potential remote code execution capabilities. Security professionals and network administrators who rely on tcpdump for network monitoring, intrusion detection, and forensic analysis face significant risk when operating vulnerable versions of the tool. Attackers could exploit this vulnerability by transmitting specially crafted AH packets to systems running affected tcpdump versions, potentially gaining unauthorized control over network analysis systems or disrupting critical network monitoring operations. The vulnerability affects any environment where tcpdump is used to process network traffic, including enterprise security operations centers, network forensics labs, and automated monitoring systems. This makes the impact particularly severe given tcpdump's widespread deployment across various network security infrastructure components.
Mitigation strategies for CVE-2016-7922 primarily focus on immediate software updates and operational security measures. The most effective solution involves upgrading to tcpdump version 4.9.0 or later, which includes proper bounds checking and input validation within the ah_print() function. Organizations should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, while monitoring for anomalous packet patterns that might indicate exploitation attempts. Additional defensive measures include deploying network intrusion detection systems with signature updates to identify and block malicious AH packets, implementing rate limiting on authentication header processing, and conducting regular vulnerability assessments to identify other potential buffer overflow vulnerabilities in network analysis tools. From a compliance perspective, this vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and may be mapped to ATT&CK technique T1059 for command and control communications. Organizations should also consider implementing network traffic filtering rules that can identify and drop malformed AH packets at network boundaries, providing an additional layer of defense against exploitation attempts.