CVE-2021-42755 : What You Need to Know
Learn about CVE-2021-42755, an integer overflow vulnerability in Fortinet products, allowing attackers to crash the dhcpd daemon, leading to a denial of service. Understand impact, affected systems, exploitation, and mitigation steps.
An integer overflow / wraparound vulnerability in Fortinet products may allow attackers to crash the dhcpd daemon, leading to a denial of service.
Understanding CVE-2021-42755
This CVE describes a specific vulnerability affecting various Fortinet products.
What is CVE-2021-42755?
CVE-2021-42755 is an integer overflow / wraparound vulnerability present in multiple Fortinet products, potentially enabling attackers to crash the dhcpd daemon and cause a denial of service.
The Impact of CVE-2021-42755
The vulnerability's impact is rated as medium severity with a CVSS base score of 4.2. It requires low attack complexity and allows unauthenticated attackers in the adjacent network to exploit it, affecting the availability of the dhcpd daemon.
Technical Details of CVE-2021-42755
This section provides more in-depth technical insights into the CVE.
Vulnerability Description
The vulnerability exists in Fortinet products such as FortiSwitch, FortiRecorder, FortiVoiceEnterprise, FortiOS, and FortiProxy. It affects specific versions of each product mentioned, allowing an unauthenticated attacker to crash the dhcpd daemon.
Affected Systems and Versions
- FortiSwitch 7.0.2 and below, 6.4.9 and below, 6.2.x, 6.0.x
- FortiRecorder 6.4.2 and below, 6.0.10 and below
- FortiOS 7.0.2 and below, 6.4.8 and below, 6.2.10 and below, 6.0.x
- FortiProxy 7.0.0, 2.0.6 and below, 1.2.x, 1.1.x, 1.0.x
- FortiVoiceEnterprise 6.4.3 and below, 6.0.10 and below
Exploitation Mechanism
The vulnerability can be exploited by an unauthenticated, network-adjacent attacker, potentially leading to a crash in the dhcpd daemon.
Mitigation and Prevention
Understanding how to mitigate and prevent the exploitation of CVE-2021-42755 is crucial.
Immediate Steps to Take
- Apply vendor-supplied patches and updates as soon as they are available.
- Monitor network traffic for any suspicious activity targeting the dhcpd daemon.
Long-Term Security Practices
- Regularly update and maintain all Fortinet products to ensure they are running the latest secure versions.
- Implement network segmentation and access controls to limit unauthorized access.
Patching and Updates
- Fortinet has likely issued patches to address this vulnerability. Ensure timely installation of these patches to secure your systems.