Vulnerability in Cisco Snort\+\+

CVE-2017-6657

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.

EPSS: 0.011 (61.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Cisco Snort\+\+
  • N/a Snort 3.0 All Versions Prior To Build 233. — versions Snort 3.0 All versions prior to build 233.

References

Frequently asked questions

What is CVE-2017-6657?
CVE-2017-6657 is a high-severity vulnerability in Cisco Snort\+\+. CVSS score: 7.5/10. Published 2017-05-16.
How severe is CVE-2017-6657?
High severity. CVSS v3 base score is 7.5 out of 10.