#VU57753 Improper Enforcement of Message Integrity During Transmission in a Communication Channel


Published: 2021-10-28

Vulnerability identifier: #VU57753

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34793

CWE-ID: CWE-924

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco Adaptive Security Appliance (ASA)
Hardware solutions / Security hardware applicances
Cisco Firepower Threat Defense (FTD)
Hardware solutions / Security hardware applicances
ASA 5500-X Series Firewalls
Other software / Other software solutions

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists in the TCP Normalizer when handling certain TCP segments. A remote attacker can send a specially crafted TCP segment through an affected device and poison MAC address tables.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service attack but requires the affected device to be operating in transparent mode.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cisco Adaptive Security Appliance (ASA): 9.7 - 9.15.1.10

ASA 5500-X Series Firewalls: All versions

Cisco Firepower Threat Defense (FTD): 6.2.3 - 6.2.3.16, 6.2.2 - 6.2.2.1, 6.3.0 - 6.3.0.6, 6.4.0 - 6.4.0.12, 6.5.0 - 6.5.0.5, 6.6.0 - 6.6.4, 6.7.0


External links
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvx46296
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.


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