cisco-sa-20180905-esa-url-bypass: Cisco Email Security Appliance URL Filtering Bypass Vulnerability
A vulnerability in the anti-spam protection mechanisms of Cisco AsyncOS Software for the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass certain content filters on an affected device. The vulnerability is due to incomplete input and validation checking mechanisms for certain Sender Policy Framework (SPF) messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. If successful, an exploit could allow the attacker to bypass the URL filters that are configured for the affected device, which could allow malicious URLs to pass through the device.
There are no workarounds that address this vulnerability.
This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-esa-url-bypass
Credit
Affected Software
Event History
Frequently Asked Questions
What is the severity of cisco-sa-20180905-esa-url-bypass?
The severity of cisco-sa-20180905-esa-url-bypass is medium with a CVSS score of 5.3.
How do I fix cisco-sa-20180905-esa-url-bypass?
To fix cisco-sa-20180905-esa-url-bypass, you should apply the latest updates and patches provided by Cisco for the Email Security Appliance.
What systems are affected by cisco-sa-20180905-esa-url-bypass?
The vulnerability affects the Cisco Email Security Appliance running Cisco AsyncOS Software.
What type of vulnerability is cisco-sa-20180905-esa-url-bypass?
cisco-sa-20180905-esa-url-bypass is a URL filtering bypass vulnerability that allows attackers to bypass content filters.
Who can exploit cisco-sa-20180905-esa-url-bypass?
An unauthenticated, remote attacker can exploit cisco-sa-20180905-esa-url-bypass to bypass certain content filters.