CVE-2021-25748 json
Ingress-nginx `path` sanitization can be bypassed with newline character
published 2023-05-24 3 y ago modified 2026-08-07 3 mo ago also GHSA-863x-868h-968x , EUVD-2023-1500
- cvss
- 7.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go k8s.io/ingress-nginx 1.2.1
- Kubernetes Kubernetes ingress-nginx 1.2.1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 21 mo ago
Exploit prediction
0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | k8s.io/ingress-nginx | <1.2.1 |
1.2.1 |
Affected products
- Kubernetes Kubernetes ingress-nginx
Classification
- Weakness
-
- CWE-20 Improper Input Validation
- Technology feeds
References
-
github.com
/kubernetes/ingress-nginx/pull/8623
web
-
groups.google.com
/g/kubernetes-security-announce/c/avaRYa9c7I8
web, mailing-list, mitigation, vendor-advisory
-
github.com
/kubernetes/ingress-nginx/issues/8686
web, issue-tracking, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-25748
advisory
-
github.com
/kubernetes/ingress-nginx
package
-
github.com
/kubernetes/ingress-nginx/releases/tag/controller-v1.2.1
web
Sources
- CVE List CVE-2021-25748
- GitHub Advisory GHSA-863x-868h-968x
- NVD CVE-2021-25748
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