CVE-2017-6657

Name: CVE-2017-6657
Creator: NVD / NIST
Published: 2017-05-16T17:29:00.403+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 1.06%

Last modified Jun 17, 2026

CVE-2017-6657 is a vulnerability of currently unknown severity. Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation. Since valid ether type and IP protocol numbers do not overlap, Snort++ stores all protocol decoders in a single array. EPSS estimates a 1.06% chance of exploitation in the next 30 days.

Description

Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation. Since valid ether type and IP protocol numbers do not overlap, Snort++ stores all protocol decoders in a single array. That makes it possible to craft packets that have IP protocol numbers in the ether type field which will confuse the Snort++ decoder. For example, an eth:llc:snap:icmp6 packet will cause a crash because there is no ip6 header with which to calculate the icmp6 checksum. Affected decoders include gre, llc, trans_bridge, ciscometadata, linux_sll, and token_ring. The fix adds a check in the packet manager to validate the ether type before indexing the decoder array. An out of range ether type will raise 116:473.

Metrics

EPSS Probability

1.06%

60.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Cisco	Snort\+\+	All versions

References

http://blog.snort.org/2017/05/snort-vulnerabilities-found.htmlThird Party Advisory
http://www.securitytracker.com/id/1038483
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170515-snortVendor Advisory
http://blog.snort.org/2017/05/snort-vulnerabilities-found.htmlThird Party Advisory
http://www.securitytracker.com/id/1038483

Timeline

Published: May 16, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-6657?

How severe is CVE-2017-6657?

Severity scoring for CVE-2017-6657 is pending analysis. The EPSS model estimates a 1.06% probability of exploitation in the next 30 days.

How do I fix CVE-2017-6657?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-6657?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST