Executive brief
tcpdump is a widely used command-line tool for monitoring and analyzing network traffic. A vulnerability in its CALM FAST protocol parser allows an attacker to trigger a buffer overflow by sending specially crafted network packets. This could lead to a complete system crash or potentially allow the attacker to execute malicious code on the system running the tool, impacting network visibility and security operations.
Technical details
A buffer overflow vulnerability exists in the CALM FAST protocol parser within tcpdump versions prior to 4.9.0. The flaw is located in the calm_fast_print() function in print-calm-fast.c and is triggered by improper bounds checking when processing network packets. An unauthenticated remote attacker can exploit this by sending specially crafted packets to a network segment where tcpdump is performing live capture, or by providing a malicious pcap file for analysis. Successful exploitation can result in a denial of service (application crash) or arbitrary code execution with the privileges of the tcpdump process. The issue is resolved in version 4.9.0.
Affected products
- tcpdump tcpdump before 4.9.0
Timeline
- 2017-01-26: patched: tcpdump 4.9.0 released fixing multiple vulnerabilities
- 2017-01-27: advisory: NVD published CVE-2016-7985