CVE-2017-6657: Input Validation
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, transbridge, ciscometadata, linuxsll, and tokenring. 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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2017-6657?
CVE-2017-6657 is rated as a medium severity vulnerability.
How do I fix CVE-2017-6657?
To fix CVE-2017-6657, update to the latest build of Cisco Snort++ as recommended by Cisco.
What impact does CVE-2017-6657 have on network security?
CVE-2017-6657 can allow an attacker to bypass security controls by exploiting the Ether Type Validation flaw.
Which versions of Cisco Snort++ are affected by CVE-2017-6657?
CVE-2017-6657 affects Cisco Snort++ versions before build 233.
Is CVE-2017-6657 an authenticated or unauthenticated vulnerability?
CVE-2017-6657 can be exploited without authentication.