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Fencer Intel
high 7.5

CVE-2018-5256 json

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/kub…

published 2018-05-18 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-17038

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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.

Patch / fix

  • redhat tectonic 1.7.9-tectonic.4, 1.8.4-tectonic.3

Exploit prediction

1.66% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.