Quick answers
- Is CVE-2016-7939 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2016-7939 being exploited in the wild.
- How severe is CVE-2016-7939?
- Critical severity, with a CVSS score of 9.8, published 28 January 2017.
- Which products and versions are affected?
- tcpdump tcpdump < 4.9.0.
- Is there a fix for CVE-2016-7939?
- A patch was published on 2017-01-28: Fixed in version 4.9.0-1 in Debian and upstream 4.9.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2016-7939 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2016-7939?
- Check whether you run Tcpdump. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A buffer overflow vulnerability exists in the GRE (Generic Routing Encapsulation) parser of tcpdump versions prior to 4.9.0. The flaw is located within multiple functions in the print-gre.c source file. A remote, unauthenticated attacker can exploit this by sending specially crafted GRE packets to a network segment where tcpdump is performing live capture, or by tricking a user into opening a malicious pcap file. Successful exploitation can result in a crash (Denial of Service) or potentially arbitrary code execution with the privileges of the tcpdump process. The issue was addressed in version 4.9.0.
Affected products
- tcpdump tcpdump < 4.9.0
Timeline
- 2017-01-27: disclosed
- 2017-01-27: advisory
- 2017-01-28: patched: Fixed in version 4.9.0-1 in Debian and upstream 4.9.0