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TcpdumpApplication

CVE-2016-7929

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 Juniper PPPoE ATM parser in tcpdump before 4.9.0 has a buffer overflow in print-juniper.c:juniper_parse_header().

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 Juniper PPPoE ATM parser (print-juniper.c:juniper_parse_header()). When parsing specially crafted Juniper PPPoE packets, the parser fails to properly validate input size before copying data into a fixed-size buffer, leading to heap or stack overflow. This can be triggered by receiving malicious network packets, potentially allowing remote code execution with the privileges of the tcpdump process.

MitigationUpgrade tcpdump to version 4.9.0 or later. If immediate upgrade is not feasible, restrict network exposure to systems running tcpdump and consider disabling PPPoE packet parsing capabilities until the upgrade can be completed.

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. Identify installed tcpdump version
    Run 'tcpdump --version' or 'rpm -q tcpdump' / 'dpkg -l tcpdump' to get the exact version number
    Affected if Version is 4.8.1 or lower (the installed version falls within <= 4.8.1)
  2. Confirm tcpdump is capturing on network segments with Juniper PPPoE traffic
    Review network topology or capture configuration to determine if Juniper PPPoE (PPPoE over ATM) packets are present on the monitored segment
    Affected if Juniper PPPoE packets are being processed by tcpdump - the parser in print-juniper.c handles these packets
  3. Check if tcpdump is running with Juniper-related BPF filters
    Review tcpdump command-line options or capture scripts for flags such as 'juniper' or PPPoE-related filters that would invoke the juniper_parse_header() function
    Affected if Filters or capture configurations explicitly invoke Juniper PPPoE parsing
  4. Identify active tcpdump processes handling PPPoE traffic
    Use 'ps aux | grep tcpdump' and 'netstat -anp' or 'ss -anp' to identify running tcpdump instances and the interfaces they are listening on, then determine if those interfaces carry PPPoE traffic
    Affected if tcpdump is actively capturing on interfaces that carry Juniper PPPoE traffic

You are affected if tcpdump version is 4.8.1 or lower AND the system is processing or likely to process Juniper PPPoE packets through the tcpdump capture process.

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. If immediate upgrade is not feasible, restrict network exposure to systems running tcpdump and consider disabling PPPoE packet parsing capabilities until the upgrade can be completed.

Recommended fix High confidence

tcpdump 4.9.0 or later

  1. 1. Identify the current tcpdump version by running: tcpdump --version or dpkg -l | grep tcpdump (Debian) / rpm -qa | grep tcpdump (Red Hat)
  2. 2. For Debian/Ubuntu systems: Run 'apt-get update' followed by 'apt-get install tcpdump' to upgrade to the latest available version
  3. 3. For Red Hat/CentOS systems: Run 'yum update tcpdump' to upgrade to the latest available version
  4. 4. For Gentoo systems: Run 'emerge --sync' and then 'emerge -av net-analyzer/tcpdump' to upgrade
  5. 5. Verify the installation was successful by checking the new version: tcpdump --version
  6. 6. Confirm the version is 4.9.0 or later which contains the fix for the Juniper PPPoE ATM parser buffer overflow

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

Fix this in Tcpdump Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing2.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,540
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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-2016-7929 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