Information disclosure in Red Hat Tectonic
CVE-2018-5256
CoreOS Tectonic 1.7.x before 1.7.9-tectonic.4 and 1.8.x before 1.8.4-tectonic.3 mounts a direct proxy to the kubernetes cluster at /api/kubernetes/ which is accessible without authentication to Tectonic and allows an attacker to directly connect to the kubernetes API server. Unauthenticated users are able to list all Namespaces through the Console, resulting in an information disclosure. Tectonic's exposure of an unauthenticated API endpoint containing information regarding the internal state of the cluster can provide an attacker with information that may assist in other attacks against the cluster. For example, an attacker may not have the permissions required to list all namespaces in the cluster but can instead leverage this vulnerability to enumerate the namespaces and then begin to check each namespace for weak authorization policies that may allow further escalation of privileges.
Vulnerability class: Information Disclosure
EPSS: 0.017 (74.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Redhat Tectonic
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (x_refsource_CONFIRM, Vendor Advisory)
- cve@mitre.org (x_refsource_CONFIRM, Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2018-5256?
- CVE-2018-5256 is a high-severity vulnerability in Red Hat Tectonic, classified under Information Disclosure. CVSS score: 7.5/10. Published 2018-05-18.
- How severe is CVE-2018-5256?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2018-5256 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.