CVE-2021-25745 is a high-severity vulnerability affecting the Kubernetes ingress-nginx component. This vulnerability allows a user with the ability to create or update ingress objects to exploit the spec.rules[].http.paths[].path field of an Ingress object. By doing so, they can obtain the credentials of the ingress-nginx controller, which, in the default configuration, grants access to all secrets within the Kubernetes cluster. The implications of this vulnerability are critical, as it could lead to unauthorized access to sensitive information and compromise the security of the entire cluster.
The CVSS score for this vulnerability is 7.6, indicating a high severity level. The attack vector is classified as network-based, with low complexity and low privileges required for exploitation. This means that an attacker does not need extensive resources or permissions to take advantage of this vulnerability, which heightens the urgency for organizations to address it promptly.
Organizations utilizing ingress-nginx should prioritize immediate remediation efforts to mitigate the risks associated with this vulnerability. The potential for exploitation is significant, as attackers may leverage this issue to gain unauthorized access to sensitive cluster secrets. It is crucial for security teams to assess their configurations and implement the necessary patches to secure their environments.
In conclusion, CVE-2021-25745 represents a serious risk for Kubernetes environments using ingress-nginx. Organizations must take swift action to remediate this vulnerability and protect their sensitive data from potential exposure.
Vulnerability Details
A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use the spec.rules[].http.paths[].path field of an Ingress object (in the networking.k8s.io or extensions API group) to obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.
The CVSS score for this vulnerability is 7.6, indicating a high severity level. It has been classified with a CVSS vector string of CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L, which highlights its network attack vector, low complexity, and the fact that low privileges are required for exploitation.
This vulnerability affects all versions of ingress-nginx prior to version 1.2.0, and it has been published on May 6, 2022. The corresponding Common Weakness Enumeration (CWE) ID for this vulnerability is CWE-20.
Technical Analysis
The root cause of this vulnerability lies in the misconfiguration of ingress-nginx where a user is granted the ability to manipulate ingress objects. Specifically, the misuse of the spec.rules[].http.paths[].path field allows the retrieval of sensitive credentials, such as service account tokens, which should remain secure and inaccessible to unauthorized users.
The attack vector for this vulnerability is network-based, meaning that an attacker can exploit it remotely. The complexity of the attack is low, as it requires only low-level privileges, making it highly accessible for potential attackers. No user interaction is required, which further increases the risk profile of this vulnerability.
The impact of this vulnerability can be significant, as the confidentiality of sensitive data is rated as high, while the integrity and availability impacts are low. This means that while the information could be accessed unlawfully, the potential for altering or disrupting services is minimal.
Risk & Impact Analysis
Risk to organizations includes unauthorized access to sensitive Kubernetes secrets, which could lead to further exploitation within the cluster. This vulnerability is particularly concerning for organizations that rely heavily on Kubernetes for their applications and services.
The blast radius of this vulnerability can be extensive, as obtaining access to cluster secrets may allow an attacker to pivot and compromise other components or services within the Kubernetes environment. Given the high severity of the CVSS score, organizations must assess their risk posture and prioritize remediation efforts.
Organizations should address this vulnerability in their priority patch cycle to minimize exposure to potential threats. The urgency is underscored by the fact that the vulnerability allows for low-complexity, high-impact exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects all versions of ingress-nginx prior to version 1.2.0. Organizations must ensure they are running updated versions to mitigate this risk.
Mitigation & Remediation
Organizations should apply patches to ingress-nginx as they become available. The recommended action is to upgrade to version 1.2.0 or later to eliminate this vulnerability. If immediate patching is not feasible, consider temporary workarounds, such as restricting access to ingress objects or modifying configurations to limit exposure.
For a comprehensive approach to security, consider engaging in penetration testing to validate the effectiveness of your remediation efforts.
Detection Guidance
Monitoring logs for unusual access patterns to ingress objects can provide early indicators of potential exploitation. Look for unauthorized attempts to modify ingress rules or access sensitive paths that may indicate an attack.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-25745 lies in its potential to expose Kubernetes environments to unauthorized access. Organizations must remain vigilant and adopt a proactive approach to security, ensuring that their configurations are secure and that they are regularly updating their software.
This vulnerability highlights the importance of strict access controls within Kubernetes clusters. Security teams should implement strict role-based access controls (RBAC) to limit permissions and minimize exposure.
For further guidance on enhancing your Kubernetes security posture, consider exploring resources like penetration testing methodology and vulnerability management program design to build a robust security framework.
In conclusion, CVE-2021-25745 serves as a critical reminder for organizations to continuously evaluate and strengthen their security measures, especially in dynamic environments like Kubernetes.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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