# CVE-2017-5486: Tcpdump buffer overflow in ISO CLNS parser

Source: https://junglewise.ai/threats/cve-2017-5486-tcpdump-buffer-overflow-in-iso-clns-parser  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2017-01-28. Updated: 2026-05-13  
License: CC BY 4.0 with a link back

CVE-2017-5486 · Severity: critical · CVSS 9.8 · Published 2017-01-28

Tcpdump, a widely used tool for monitoring and analyzing network traffic, contains a vulnerability in its ISO CLNS protocol parser. An attacker can exploit this by sending specially crafted network packets to a system running tcpdump, potentially causing the application to crash or allowing for unauthorized code execution. This could lead to a complete system compromise or a disruption of network monitoring capabilities.

Technologies: [Tcpdump](https://junglewise.ai/threats/technologies/tcpdump). Vendors: [Tcpdump](https://junglewise.ai/threats/vendors/tcpdump).

## Quick answers

**Is CVE-2017-5486 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2017-5486 being exploited in the wild.

**How severe is CVE-2017-5486?** Critical severity, with a CVSS score of 9.8, published 28 January 2017.

**Which products and versions are affected?** tcpdump tcpdump < 4.9.0.

**Is there a fix for CVE-2017-5486?** A patch was published on 2017-01-29: Debian security update released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2017-5486 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2017-5486?** 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 tcpdump versions prior to 4.9.0 within the ISO Connectionless Network Service (CLNS) parser, specifically in the clnp_print() function located in print-isoclns.c. The flaw is triggered when the utility processes malformed packets, either during live capture or when reading a crafted pcap file. Because tcpdump often runs with elevated privileges to capture raw network traffic, a successful exploit could allow a remote, unauthenticated attacker to execute arbitrary code or cause a denial-of-service (DoS) condition via a crash. The vulnerability is addressed in version 4.9.0.

## Affected products

- tcpdump tcpdump < 4.9.0

## Timeline

- 2017-01-26: disclosed: Initial report in Debian bug tracking system
- 2017-01-28: advisory: NVD publication date
- 2017-01-29: patched: Debian security update released

## References

- [http://www.debian.org/security/2017/dsa-3775](http://www.debian.org/security/2017/dsa-3775)
- [http://www.securityfocus.com/bid/95852](http://www.securityfocus.com/bid/95852)
- [http://www.securitytracker.com/id/1037755](http://www.securitytracker.com/id/1037755)
- [https://access.redhat.com/errata/RHSA-2017:1871](https://access.redhat.com/errata/RHSA-2017:1871)
- [https://security.gentoo.org/glsa/201702-30](https://security.gentoo.org/glsa/201702-30)
- [https://www.mail-archive.com/debian-bugs-dist%40lists.debian.org/msg1494526.html](https://www.mail-archive.com/debian-bugs-dist%40lists.debian.org/msg1494526.html)

## Related threats

- [Tcpdump buffer overflow in ISO CLNS parser lookup_nsap function](https://junglewise.ai/threats/cve-2017-5485-tcpdump-buffer-overflow-in-iso-clns-parser-lookup-nsap-function)
- [Tcpdump buffer overflow in ATM parser sig_print function](https://junglewise.ai/threats/cve-2017-5484-tcpdump-buffer-overflow-in-atm-parser-sig-print-function)
- [tcpdump buffer overflow in SNMP parser](https://junglewise.ai/threats/cve-2017-5483-tcpdump-buffer-overflow-in-snmp-parser)
- [tcpdump buffer overflow in Q.933 parser](https://junglewise.ai/threats/cve-2017-5482-tcpdump-buffer-overflow-in-q-933-parser)
- [tcpdump buffer overflow in multiple protocol parsers](https://junglewise.ai/threats/cve-2017-5342-tcpdump-buffer-overflow-in-multiple-protocol-parsers)