Cisco Email Security Appliance Content Filter Attachment input validation

Summaryinfo

A vulnerability, which was classified as critical, has been found in Cisco Email Security Appliance. This affects an unknown part of the component Content Filter. This manipulation as part of Attachment causes input validation. This vulnerability is registered as CVE-2019-1921. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Cisco Email Security Appliance (Anti-Malware Software) (affected version unknown) and classified as critical. Affected by this vulnerability is an unknown functionality of the component Content Filter. The manipulation as part of a Attachment leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability in the attachment scanning of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper input validation of the email body. An attacker could exploit this vulnerability by naming a malicious attachment with a specific pattern. A successful exploit could allow the attacker to bypass configured content filters that would normally block the attachment.

The weakness was published 07/06/2019 as cisco-sa-20190703-esa-bypass as confirmed advisory (Website). The advisory is shared at tools.cisco.com. This vulnerability is known as CVE-2019-1921 since 12/06/2018. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/18/2023).

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Anti-Malware Software

Vendor

• Cisco

Name

• Email Security Appliance

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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