Security readout for executives and security teams
Plain-English summary
CVE-2021-25745 lets someone who already can create or update Kubernetes Ingress objects abuse an ingress-nginx path value to obtain the ingress-nginx controller credentials. In the default configuration, those credentials can read all cluster secrets, making this a serious internal privilege-escalation and data-exposure risk.
Executive priority
Treat as high priority where Kubernetes clusters allow delegated Ingress management. A compromised tenant or CI credential could expose cluster secrets through controller credentials, potentially affecting application credentials, tokens, and operational trust boundaries.
Technical view
The vulnerable surface is Kubernetes ingress-nginx handling of spec.rules[].http.paths[].path in networking.k8s.io or extensions Ingress objects. A low-privileged Kubernetes user with Ingress create/update rights can cause credential disclosure for the ingress-nginx controller. The CVSS 3.1 score is 7.6 with high confidentiality impact.
Likely exposure
Clusters using Kubernetes ingress-nginx are most exposed when non-administrators, automation, or tenants can create or update Ingress resources. Risk is higher if the controller service account keeps default broad access to cluster secrets.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires authenticated Kubernetes privileges to create or update Ingress objects, but no user interaction and low attack complexity are indicated by the CVSS vector.
Researcher notes
The evidence identifies the vulnerable field, required privilege, API groups, and default secret-access consequence. The provided bundle does not name affected ingress-nginx versions, fixed versions, or confirmed exploitation, so validation should center on deployed ingress-nginx, RBAC exposure, and vendor advisory status.
Mitigation direction
- Review Kubernetes ingress-nginx advisory guidance for supported fixed versions or configuration changes.
- Restrict who can create or update Ingress resources in affected clusters.
- Reduce ingress-nginx controller service account permissions, especially access to secrets.
- Audit tenant, CI/CD, and automation roles with Ingress write privileges.
- Check NetApp advisory relevance if using affected NetApp-integrated Kubernetes environments.
Validation and detection
- Inventory clusters running Kubernetes ingress-nginx.
- List subjects with create or update permissions on Ingress resources.
- Review ingress-nginx controller service account permissions to Kubernetes secrets.
- Check existing Ingress objects for unexpected or untrusted path definitions.
- Confirm remediation status against vendor advisory and issue references.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-25745 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L2.84.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.6HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://groups.google.com/g/kubernetes-security-announce/c/7vQrpDZeBlcCVE reference · x_refsource_MISC
- https://github.com/kubernetes/ingress-nginx/issues/8502CVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20220609-0006/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.