CVE-2017-6657
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.06%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.06% probability · 63th percentile
- CISA KEV
- Not listed
- Affected
- cisco/snort\+\+
- Source
- psirt@cisco.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.