cisco-sa-20191002-esa-bypass: Cisco Email Security Appliance Filter Bypass Vulnerability
A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the configured user filters on an affected device. The vulnerability exists because the affected software insufficiently validates certain incoming SPF messages. An attacker could exploit this vulnerability by sending a custom SPF packet to an affected device. A successful exploit could allow the attacker to bypass the configured header filters, which could allow malicious content to pass through the device. Cisco has released software updates that address this vulnerability. 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-20191002-esa-bypass
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Affected Software
Event History
Frequently Asked Questions
What is the severity of cisco-sa-20191002-esa-bypass?
The severity of cisco-sa-20191002-esa-bypass has been classified as high due to its potential for exploitation without authentication.
How do I fix cisco-sa-20191002-esa-bypass?
To fix cisco-sa-20191002-esa-bypass, it is recommended to update your Cisco Email Security Appliance to the latest firmware version provided by Cisco.
What could an attacker achieve by exploiting cisco-sa-20191002-esa-bypass?
An attacker exploiting cisco-sa-20191002-esa-bypass could bypass user filters, allowing unauthorized access to potentially harmful messages.
Which devices are affected by cisco-sa-20191002-esa-bypass?
cisco-sa-20191002-esa-bypass affects all versions of Cisco Email Security Appliance that utilize the Sender Policy Framework functionality.
Is authentication required to exploit cisco-sa-20191002-esa-bypass?
No, authentication is not required to exploit cisco-sa-20191002-esa-bypass, making it a critical security concern.