CVE-2017-16808 in tcpdump
Summary
by MITRE
tcpdump 4.9.2 has a heap-based buffer over-read related to aoe_print in print-aoe.c and lookup_emem in addrtoname.c.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-16808 represents a critical heap-based buffer over-read condition affecting tcpdump version 4.9.2. This issue manifests within the address resolution functionality of the network packet analysis tool, specifically in two distinct functions that handle address-to-name resolution. The flaw occurs when tcpdump processes certain network packets containing Address Resolution Protocol over Ethernet (AOE) data structures, creating a scenario where the application reads memory beyond the allocated buffer boundaries. The vulnerability is particularly concerning as it exists within the print-aoe.c and addrtoname.c source files, indicating a cross-module impact that extends beyond simple address resolution.
The technical root cause of this vulnerability stems from inadequate bounds checking during the processing of AOE protocol packets. When tcpdump encounters packets with malformed or unexpected AOE header structures, the aoe_print function in print-aoe.c fails to properly validate the length of data being processed before attempting to read from memory locations that may extend beyond the intended buffer limits. Similarly, the lookup_emem function in addrtoname.c exhibits comparable behavior when handling memory lookups for address resolution. This type of buffer over-read vulnerability is classified under CWE-125 as an "Out-of-bounds Read" and represents a common class of memory safety issues that can lead to unpredictable application behavior, potential information disclosure, or even remote code execution under specific conditions. The ATT&CK framework categorizes this as a memory corruption technique under the T1059.007 sub-technique related to command and scripting interpreter.
The operational impact of CVE-2017-16808 extends beyond simple application instability, as it creates potential attack vectors for adversaries seeking to exploit network monitoring tools. When an attacker can manipulate network traffic to trigger this vulnerability, they may be able to cause tcpdump to read sensitive memory regions, potentially exposing system information, credentials, or other confidential data. The heap-based nature of the over-read means that the vulnerability could be exploited in ways that are difficult to detect and predict, making it particularly dangerous in environments where tcpdump is used for security monitoring and network analysis. This vulnerability affects any system running tcpdump 4.9.2 that processes network packets containing AOE protocol data, creating a significant risk for network administrators and security professionals who rely on this tool for traffic analysis and intrusion detection.
Mitigation strategies for CVE-2017-16808 should prioritize immediate patching of tcpdump installations to versions that contain proper bounds checking and memory validation. Organizations should also implement network segmentation and monitoring to limit the exposure of systems running tcpdump to potentially malicious traffic. Additional protective measures include configuring tcpdump to process only trusted network traffic, implementing network access controls to prevent unauthorized packet injection, and establishing robust monitoring for unusual tcpdump behavior that might indicate exploitation attempts. Security teams should also consider implementing intrusion detection systems that can identify patterns associated with this specific vulnerability, as well as conducting regular vulnerability assessments to identify other potential memory safety issues within network monitoring tools. The remediation process should include comprehensive testing to ensure that patched versions maintain functionality while eliminating the buffer over-read condition.