Quick answers
- Is CVE-2016-7993 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2016-7993 being exploited in the wild.
- How severe is CVE-2016-7993?
- Critical severity, with a CVSS score of 9.8, published 28 January 2017.
- Which products and versions are affected?
- tcpdump tcpdump before 4.9.0.
- Is there a fix for CVE-2016-7993?
- A patch was published on 2017-01-26: Upstream release 4.9.0 published Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2016-7993 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2016-7993?
- 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 relts_print() function within util-print.c of tcpdump versions prior to 4.9.0. The flaw is triggered during the parsing of relative timestamps in several protocol handlers, including DNS, DVMRP, HSRP, IGMP, lightweight resolver protocol, and PIM. An attacker can exploit this by sending specially crafted packets over the network or providing a malicious pcap file for offline analysis. Successful exploitation can lead to a crash (Denial of Service) or potentially arbitrary code execution with the privileges of the tcpdump process. The issue is addressed in tcpdump version 4.9.0.
Affected products
- tcpdump tcpdump before 4.9.0
Timeline
- 2016-10-13: disclosed: CVE assigned date
- 2017-01-26: patched: Upstream release 4.9.0 published
- 2017-01-28: advisory: NVD publication date