CVE-2021-25748: kubernetes ingress-nginx Improper Input Validation
Vulnerability summary
CVE-2021-25748 is a high (CVSS 7.6) Improper Input Validation vulnerability in kubernetes ingress-nginx. EPSS estimates a 0.69% chance of exploitation in the next 30 days, higher than 52% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 5Timeline
- 24-05-2023PublishedVulnerability first disclosed.
- 16-01-2025Last modifiedVulnerability information updated.
Description
A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use a newline character to bypass the sanitization of 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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · GoEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NDiffers
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NDiffers
EPSS trend
Probability
0.69%
Chance of exploitation in the next 30 days
Percentile
52%
Versus all other CVEs
30-day change
0.00 pp
From 0.69% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Kubernetes2 products
- ingress-nginx< 1.2.1
- kubernetes ingress-nginx≥ unspecified, < 1.2.1
K8s.io1 product
- ingress-nginx< 1.2.1
2 vendors · 3 products
References
6 links- groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8WEBMailing ListMitigationVendor Advisory
