Executive brief
A vulnerability in Cisco's email security gateway could allow an attacker to bypass security filters by sending specially crafted email attachments. This could result in malicious files or prohibited content reaching employee inboxes despite active security policies. Successful exploitation could lead to malware infections or the circumvention of corporate data protection rules.
Technical details
The vulnerability exists in the content scanning engine of Cisco AsyncOS Software due to improper input validation of email attachments in various formats. An unauthenticated, remote attacker can exploit this by sending a crafted email message with a specific attachment to the Cisco Email Security Appliance (ESA). If the ESA is configured with message or content filters, the crafted attachment may bypass these security checks, allowing potentially malicious content to pass through the device. The issue is tracked under Cisco Bug ID CSCuz16076 and is fixed in AsyncOS versions 10.0.1-083 and 10.0.1-087.
Affected products
- Cisco AsyncOS for Email Security Appliance (ESA) All releases prior to 10.0.1-083; 9.7.1-066, 9.7.1-HP2-207, 9.8.5-085
Timeline
- 2017-01-18: advisory: Initial Cisco advisory published
- 2017-01-26: disclosed: NVD publication date