Vulnerability Details : CVE-2021-34793
A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.
Vulnerability category: Denial of service
Products affected by CVE-2021-34793
- cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*
- Cisco » Adaptive Security Appliance SoftwareVersions from including (>=) 9.16.0 and before (<) 9.16.2.3cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
- Cisco » Adaptive Security Appliance SoftwareVersions from including (>=) 9.13.0 and before (<) 9.14.3.9cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
- Cisco » Adaptive Security Appliance SoftwareVersions from including (>=) 9.9.0 and before (<) 9.12.4.29cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
- Cisco » Adaptive Security Appliance SoftwareVersions from including (>=) 9.15.0 and before (<) 9.15.1.17cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5505_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5512-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5515-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5525-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5545-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5555-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5580_firmware:009.008\(004.025\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:asa_5585-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-34793
0.09%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 23 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-34793
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
5.0
|
MEDIUM | AV:N/AC:L/Au:N/C:N/I:N/A:P |
10.0
|
2.9
|
NIST | |
|
8.6
|
HIGH | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
3.9
|
4.0
|
Cisco Systems, Inc. | |
|
8.6
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
3.9
|
4.0
|
NIST |
CWE ids for CVE-2021-34793
-
The product establishes a communication channel with an endpoint and receives a message from that endpoint, but it does not sufficiently ensure that the message was not modified during transmission.Assigned by:
- nvd@nist.gov (Primary)
- ykramarz@cisco.com (Secondary)
References for CVE-2021-34793
-
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Transparent Mode Denial of Service VulnerabilityVendor Advisory
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