TcpdumpApplication

CVE-2016-7923

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 ARP parser in tcpdump before 4.9.0 has a buffer overflow in print-arp.c:arp_print().

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

Buffer overflow vulnerability in tcpdump's ARP parser (print-arp.c:arp_print()) allowing potential remote code execution via maliciously crafted ARP packets. The overflow occurs when parsing ARP responses with oversized hardware address fields.

MitigationUpgrade tcpdump to version 4.9.0 or later which contains the fix for this vulnerability.

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. Check if tcpdump is installed
    Run 'tcpdump --version' or 'which tcpdump' to confirm tcpdump is present on the system
    Affected if tcpdump is not installed or not found, then this CVE does not apply
  2. Determine the installed tcpdump version
    Run 'tcpdump --version' and examine the output for the version number (e.g., 4.8.1, 4.7.4, etc.)
    Affected if The version number is 4.8.1 or lower, indicating the vulnerable version is installed
  3. Verify the binary is the original tcpdump and not a patched version
    Check if the installed binary matches the distribution's package and has not been manually replaced with a fixed version
    Affected if The binary is the original vulnerable version from the affected range and has not been rebuilt or patched
  4. Confirm ARP packet capture is possible in the environment
    Determine if the system can capture network traffic containing ARP packets (e.g., running tcpdump on a network interface, using tcpdump to capture live traffic or pcap files containing ARP)
    Affected if tcpdump is used to capture or analyze network traffic where ARP packets may be present, enabling the vulnerable code path in arp_print()

The system is affected if tcpdump version 4.8.1 or lower is installed and is being used to parse ARP packets, triggering the buffer overflow in the arp_print() function.

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 which contains the fix for this vulnerability.

Recommended fix High confidence

tcpdump 4.9.0 or later

  1. Check current tcpdump version: tcpdump --version
  2. Update your system's package repository metadata
  3. Upgrade tcpdump package using your system's package manager (e.g., apt-get update && apt-get install tcpdump, yum update tcpdump, or dnf update tcpdump)
  4. Verify the installed version is 4.9.0 or later: tcpdump --version

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

Fix this in Tcpdump Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-7923 — 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-2016-7923 in production — separate from our analysis above.

No notes yet

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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