MitM atack in Cisco Email Security Appliance and Cisco Web Security Appliance
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2021-1566 |
| CWE-ID | CWE-295 |
| Exploitation vector | Local network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Cisco AsyncOS for Web Security Appliances Server applications / IDS/IPS systems, Firewalls and proxy servers Cisco AsyncOS for Cisco Email Security Appliance Server applications / IDS/IPS systems, Firewalls and proxy servers |
| Vendor |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
1) Improper Certificate Validation
EUVDB-ID: #VU54172
Risk: Medium
CVSSv3.1: 5.5 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-1566
CWE-ID:
CWE-295 - Improper Certificate Validation
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to preform MitM attack.
The vulnerability exists due to improper certificate validation when establishing TLS connection. A remote attacker can perform a man-in-the-middle (MitM) attack.
Install updates from vendor's website.
Vulnerable software versionsCisco AsyncOS for Web Security Appliances: before 12.5.1 043
Cisco AsyncOS for Cisco Email Security Appliance: before 13.5.3 010
External linkshttp://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-cert-vali-n8L97RW
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvw08342
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvw08378
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
