CVE-2017-5486
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 · uneditedThe ISO CLNS parser in tcpdump before 4.9.0 has a buffer overflow in print-isoclns.c:clnp_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 confidenceA buffer overflow vulnerability exists in the ISO CLNS (Connectionless Network Service) packet parser in tcpdump versions prior to 4.9.0. The overflow occurs in the clnp_print() function within print-isoclns.c when parsing specially crafted CLNS packets, potentially allowing remote code execution or denial of service.
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<= 4.8.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check if tcpdump is installedRun 'tcpdump --version' or check via package manager (e.g., 'rpm -q tcpdump', 'dpkg -l tcpdump')Affected if tcpdump is not installed or the command fails, the system is not affected by this specific vulnerability
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Determine installed tcpdump versionExamine the version string from the previous check. Look for the release number (e.g., 4.8.1, 4.7.0, etc.)Affected if The version number is 4.8.1 or lower, making the installation vulnerable
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Verify the tcpdump binary can parse CLNS packetsRun 'tcpdump -v -i <interface> 2>&1 | head' or check if CLNS-related options appear in 'tcpdump -h' output; alternatively, examine the binary for isoclns parsing support via 'strings <path_to_tcpdump> | grep -i clns'Affected if tcpdump has CLNS parsing capability enabled and the version is 4.8.1 or earlier
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Check for active network traffic using CLNS protocolsMonitor network interfaces for ISO CLNS traffic (often on token ring, FDDI, or certain serial interfaces); run 'tcpdump -i <interface> -c 10 -v' and examine output for 'CLNS' or 'ISO' protocol indicatorsAffected if The system actively parses CLNS packets from network traffic, exposing the vulnerability
A system is affected if tcpdump version 4.8.1 or earlier is installed and configured to parse ISO CLNS network packets.
Generated from the published advisory. Verify against your own configuration.
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 · scopedUpgrade tcpdump to version 4.9.0 or later to resolve the buffer overflow vulnerability in the CLNS parser.
tcpdump 4.9.0 or later
- Check current tcpdump version using 'tcpdump --version' or 'rpm -q tcpdump' / 'dpkg -l tcpdump'
- 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' or 'dnf update tcpdump' for RHEL/CentOS/Fedora, 'emerge --ask net-analyzer/tcpdump' for Gentoo)
- Verify the installed version is 4.9.0 or later using 'tcpdump --version'
- Test that tcpdump functions correctly with your typical capture commands
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-5486 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2017-5486 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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