CVE-2018-0389 : Exploit Details and Defense Strategies

Cisco Small Business SPA514G IP Phones SIP Denial of Service Vulnerability

Understanding CVE-2018-0389

This CVE involves a weakness in the Session Initiation Protocol (SIP) processing in Cisco Small Business SPA514G IP Phones, allowing unauthorized remote attackers to cause a denial of service (DoS) situation.

What is CVE-2018-0389?

The vulnerability arises from improper handling of SIP request messages by the affected device, enabling attackers to send manipulated SIP messages that render the device unresponsive, leading to a persistent DoS condition.

The Impact of CVE-2018-0389

CVSS Base Score: 7.5 (High)
Attack Vector: Network
Availability Impact: High
This vulnerability does not impact confidentiality or integrity but can result in a DoS situation until manual restart.

Technical Details of CVE-2018-0389

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in SIP processing allows attackers to make the device unresponsive, causing a DoS condition.

Affected Systems and Versions

Product: Cisco Small Business SPA500 Series IP Phones
Vendor: Cisco
Versions Affected: <= 7.6.2SR2

Exploitation Mechanism

Attack Complexity: Low
Privileges Required: None
Scope: Unchanged
Attack Vector: Network
User Interaction: None
Vector String: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Mitigation and Prevention

Guidelines to mitigate the impact of CVE-2018-0389.

Immediate Steps to Take

Monitor vendor updates for patches addressing the vulnerability.
Implement network-level controls to filter potentially malicious SIP traffic.

Long-Term Security Practices

Regularly update firmware and software to the latest versions.
Conduct security assessments and penetration testing to identify vulnerabilities.

Patching and Updates

Apply patches provided by Cisco to address the SIP DoS vulnerability.