CVE-2021-40368 : Security Advisory and Response
Learn about CVE-2021-40368 affecting Siemens SIMATIC S7-400 series CPUs, allowing attackers to create a Denial-of-Service condition. Find mitigation steps and long-term security measures.
A vulnerability has been identified in SIMATIC S7-400 series and related CPUs. Attackers can initiate a Denial-of-Service condition by sending crafted packets to port 102/tcp.
Understanding CVE-2021-40368
This CVE affects various Siemens SIMATIC S7-400 CPU models and related versions, allowing attackers to disrupt normal operations.
What is CVE-2021-40368?
- CVE ID: CVE-2021-40368
- CWE Id: CWE-119
- CVSS Base Score: 7.5 (HIGH)
- CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C
- Published Date: April 12, 2022
- Last Updated: April 11, 2023
- Affected Devices: SIMATIC S7-400 series, SIPLUS variants
- Vulnerability Description: Improper handling of specially crafted packets leading to a Denial-of-Service threat.
The Impact of CVE-2021-40368
- Attackers can disrupt normal operations on affected Siemens devices.
- A crafted packet to port 102/tcp can trigger a Denial-of-Service condition.
- Restart is required to restore full functionality.
Technical Details of CVE-2021-40368
A detailed overview of the vulnerability and its implications on Siemens SIMATIC devices.
Vulnerability Description
- Affected devices mishandle packets sent to port 102/tcp, leading to a potential Denial-of-Service risk.
Affected Systems and Versions
- Several SIMATIC S7-400 CPU models are impacted, including specific versions that are vulnerable.
Exploitation Mechanism
- Crafted packets sent to port 102/tcp can exploit the vulnerability, causing disruption.
Mitigation and Prevention
Steps to safeguard devices against CVE-2021-40368 for short-term security and long-term prevention.
Immediate Steps to Take
- Monitor network traffic for any suspicious activities targeting port 102/tcp.
- Implement firewall rules to restrict unauthorized access to affected devices.
- Consider network segmentation to contain potential attacks.
Long-Term Security Practices
- Regularly update firmware and security patches provided by Siemens.
- Conduct security assessments and penetration tests to identify vulnerabilities proactively.
- Educate personnel about cybersecurity best practices to enhance overall resilience.
Patching and Updates
- Apply the necessary security updates and patches released by Siemens to address the vulnerability effectively.