TcpdumpApplication

CVE-2016-7986

CRITICAL · 9.8 CVSS v3.0 Published 2017-01-28
Fix available
A fix is available. Upgrade to after 4.8.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The GeoNetworking parser in tcpdump before 4.9.0 has a buffer overflow in print-geonet.c, multiple functions.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A buffer overflow vulnerability exists in tcpdump's GeoNetworking parser (print-geonet.c) affecting versions before 4.9.0. The overflow occurs in multiple functions within the parser that process GeoNetworking protocol packets, allowing potential remote code execution when tcpdump parses malicious network packets.

MitigationUpgrade tcpdump to version 4.9.0 or later to obtain the patched GeoNetworking parser. If upgrading is not immediately feasible, restrict tcpdump's exposure to untrusted networks and avoid processing packets from unknown sources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TcpdumpApplication
Affected:<= 4.8.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify tcpdump is installed
    Run 'tcpdump --version' or check package manager output (rpm -q tcpdump / dpkg -l tcpdump)
    Affected if tcpdump command executes and returns version information
  2. Determine installed tcpdump version
    Parse the version string from the output of 'tcpdump --version' - look for the release number (e.g., 4.8.1, 4.7.4, etc.)
    Affected if The version number is 4.8.1 or earlier (any version <= 4.8.1)
  3. Check if tcpdump processes network traffic
    Identify whether tcpdump is running or scheduled to run on network interfaces, or whether it is used to read pcap files that may contain GeoNetworking packets
    Affected if tcpdump is actively parsing live network traffic or processing pcap files that could include GeoNetworking protocol packets from the CVE description (print-geonet.c parser)
  4. Confirm GeoNetworking parser is reachable
    If using tcpdump interactively, run 'tcpdump -i <interface> -v | grep -i geo' or test with a pcap file containing GeoNetworking packets to see if the parser is invoked
    Affected if The GeoNetworking parser (print-geonet.c) processes packets - this is the component with the buffer overflow vulnerability

You are affected if tcpdump version 4.8.1 or earlier is installed AND the tool is parsing or could parse GeoNetworking protocol packets from network traffic or pcap files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 4.8.1
Interim mitigation

Upgrade tcpdump to version 4.9.0 or later to obtain the patched GeoNetworking parser. If upgrading is not immediately feasible, restrict tcpdump's exposure to untrusted networks and avoid processing packets from unknown sources.

Recommended fix High confidence

tcpdump 4.9.0 or later

  1. 1. Check the current installed version of tcpdump: tcpdump --version
  2. 2. Upgrade tcpdump to version 4.9.0 or later using your system's package manager (e.g., apt-get update && apt-get install tcpdump for Debian/Ubuntu, yum update tcpdump for RHEL/CentOS, or emerge --sync && emerge -av net-analyzer/tcpdump for Gentoo)
  3. 3. Verify the upgrade was successful by running: tcpdump --version
  4. 4. Confirm the version number is 4.9.0 or higher

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tcpdump Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA6.0 h
32.0 hours of engineering $5,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,024.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-7986 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-7986 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data