#VU54899 Reachable Assertion in Cisco Adaptive Security Appliance (ASA) - CVE-2021-1422

Vulnerability identifier: #VU54899

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-1422

CWE-ID: CWE-617

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco Adaptive Security Appliance (ASA)
Hardware solutions / Security hardware applicances

Vendor: Cisco Systems, Inc

Description

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

The vulnerability exists due to a logic error in how the software cryptography module handles specific types of decryption errors. A remote user can send malicious packets over an established IPsec connection and perform a denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco Adaptive Security Appliance (ASA): 9.16.1

---

External links
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ipsec-dos-TFKQbgWC
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvy66711

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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