CVE-2017-3793
A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD…
Does this matter?
Lower severity and a low EPSS score (1.71%). Track it; it rarely justifies an emergency change on its own.
Description
A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD to drop any further incoming traffic on all interfaces, resulting in a denial of service (DoS) condition. The vulnerability is due to improper limitation of the global out-of-order TCP queue for specific block sizes. An attacker could exploit this vulnerability by sending a large number of unique permitted TCP connections with out-of-order segments. An exploit could allow the attacker to exhaust available blocks in the global out-of-order TCP queue, causing the dropping of any further incoming traffic on all interfaces and resulting in a DoS condition. Cisco Bug IDs: CSCvb46321.
- CVSS 3.0
- 4.0 MEDIUMCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
- EPSS
- 1.71% probability · 76th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-399, CWE-400
- Affected
- cisco/adaptive security appliance software
- Source
- psirt@cisco.com
References
- http://www.securityfocus.com/bid/97923Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038329
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-normVendor Advisory
- http://www.securityfocus.com/bid/97923Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038329
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-normVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.