CVE-2021-23018 is a high-severity vulnerability affecting the F5 NGINX Controller. This vulnerability allows intra-cluster communication to occur without the use of TLS, meaning that services within the NGINX Controller 3.x namespace prior to version 3.4.0 are operating using unencrypted protocols. The lack of encryption increases the risk of data interception and unauthorized access to sensitive information.
With a CVSS score of 7.4, this vulnerability is classified as high severity. Organizations that utilize affected versions of the NGINX Controller should be particularly concerned, as it poses a significant risk to confidentiality and integrity.
Risk to organizations includes potential exposure of sensitive data transmitted within the cluster. Attackers may leverage this vulnerability to intercept communications, leading to unauthorized access to critical systems and information.
Organizations should prioritize patching immediately. The recommended course of action is to upgrade to NGINX Controller version 3.4.0 or later, where this issue has been addressed.
Given the high potential impact, it is imperative for organizations to act swiftly to mitigate this vulnerability.
Vulnerability Details
The official description of CVE-2021-23018 states: 'Intra-cluster communication does not use TLS. The services within the NGINX Controller 3.x before 3.4.0 namespace are using cleartext protocols inside the cluster.'
This vulnerability is classified under CWE-319, which pertains to the lack of encryption for sensitive data in transit. The CVSS 3.1 base score is 7.4, with a high attack complexity and no privileges required to exploit.
Affected products include any version of NGINX Controller from 3.0.0 up to, but not including, 3.4.0. This vulnerability was published on June 1, 2021.
Technical Analysis
The root cause of this vulnerability lies in the decision to use cleartext protocols for intra-cluster communication. This design oversight fails to protect sensitive data from interception during transmission.
The attack vector is classified as network-based, meaning that an attacker would need network access to exploit this vulnerability. The attack complexity is rated as high, indicating that a successful attack may require advanced skills or knowledge.
No user interaction is required for exploitation, and the vulnerability impacts confidentiality and integrity. There is no impact on availability, making this a serious issue for data security.
Risk & Impact Analysis
Real-world risk from CVE-2021-23018 includes exposure of sensitive data that is transferred within the cluster. Organizations using affected versions may experience unauthorized access to data and systems, leading to breaches and potential data loss.
The blast radius for this vulnerability can be significant, especially in environments where sensitive data is frequently communicated between services. Organizations should assess their internal architecture to understand the full scope of the risk.
The urgency for remediation is high. With the CVSS score indicating a considerable threat, organizations should incorporate this vulnerability into their immediate patching cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of the F5 NGINX Controller include all versions prior to 3.4.0, specifically from 3.0.0 up to 3.4.0.
Mitigation & Remediation
To remediate this vulnerability, organizations should upgrade to NGINX Controller version 3.4.0 or later. If immediate upgrade is not possible, consider implementing network controls to restrict intra-cluster communication and monitor for unauthorized access attempts.
For comprehensive security, organizations are encouraged to adopt penetration testing to identify and address similar vulnerabilities.
Detection Guidance
Organizations should monitor logs for indicators such as unauthorized access attempts and unusual network traffic patterns. Behavioral anomalies within the application and system changes should be closely observed to detect potential exploitation of this vulnerability.
AppSecure Threat Intelligence Insight
CVE-2021-23018 highlights the importance of securing internal communications within clusters. As organizations increasingly rely on cloud-native architectures, the lack of encryption in intra-cluster communication can have severe consequences.
This vulnerability exhibits a trend towards the necessity of implementing robust encryption protocols in all forms of data transmission, especially in clustered environments. Security teams should conduct regular assessments to ensure compliance with encryption standards.
Organizations can benefit from a proactive approach by integrating penetration testing methodologies into their security programs to identify vulnerabilities before they can be exploited.
Furthermore, organizations should remain vigilant of potential threats by staying informed about emerging vulnerabilities and integrating best practices in security protocols.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)