Zip Content Filter Bypass in Cisco Email Security Appliance

1) Input validation error

EUVDB-ID: #VU48161

Risk: Medium

CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26082

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass content filters that are configured on an affected device.

The vulnerability exists due to improper handling of password-protected zip files. A remote attacker can send a malicious file inside a specially crafted zip-compressed file and bypass configured content filters that would normally drop the email.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco AsyncOS for Cisco Email Security Appliance: 13.5.0 - 13.5.1

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-zip-bypass-gbU4gtTg

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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