CVE-2019-15988 : Security Advisory and Response

Cisco Email Security Appliance URL Filtering Bypass Vulnerability

Understanding CVE-2019-15988

This CVE involves a vulnerability in the antispam protection mechanisms of Cisco Email Security Appliance (ESA) that could allow remote attackers to bypass URL reputation filters.

What is CVE-2019-15988?

The vulnerability in Cisco Email Security Appliance (ESA) allows unauthorized remote attackers to manipulate URLs to bypass URL reputation filters, potentially enabling the transmission of malicious URLs.

The Impact of CVE-2019-15988

Successful exploitation of this vulnerability could lead to the circumvention of URL reputation filters on the affected device, allowing potentially harmful URLs to pass through.

Technical Details of CVE-2019-15988

The following technical details provide insight into the vulnerability and its implications:

Vulnerability Description

The vulnerability is present in the antispam protection mechanisms of Cisco Email Security Appliance (ESA).
It results from insufficient input validation of URLs, enabling attackers to craft URLs in a specific manner.

Affected Systems and Versions

Product: Cisco Email Security Appliance (ESA)
Vendor: Cisco
Version: Unspecified

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Base Score: 5.8 (Medium)
Vector String: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Mitigation and Prevention

To address CVE-2019-15988, consider the following mitigation strategies:

Immediate Steps to Take

Apply vendor-provided patches or updates promptly.
Monitor network traffic for any signs of exploitation.

Long-Term Security Practices

Regularly update and patch all software and systems.
Implement strong URL filtering and validation mechanisms.

Patching and Updates

Refer to the vendor's security advisory for specific patch details and instructions.