Security restrictions bypass in Cisco Web Security Appliance

1) Security restrictions bypass

EUVDB-ID: #VU17427

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-2019-1672

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass security restrictions on the system.

The vulnerability exists in the Decryption Policy Default Action functionality due to the incorrect handling of SSL-encrypted traffic when Decrypt for End-User Notification is disabled in the configuration. A remote attacker can send a SSL connection through the affected device to bypass a configured drop policy to block specific SSL connections and allow traffic onto the network that should have been denied.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco Web Security Appliance: 10.1.0 204 - 11.5.1 FCS 115

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190206-wsa-bypass

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.