Auth bypass in Etcd
CVE-2018-16886
etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.040 (90.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 90.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.040 · newest: 0.040 · change: 0.000
Affected products
- Etcd
- The Etcd Project Etcd: — versions versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11
- Fedoraproject Fedora — versions 30
- Red Hat Enterprise Linux Desktop — versions 7.0
- Red Hat Enterprise Linux Server — versions 7.0
- Red Hat Enterprise Linux Workstation — versions 7.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG… (Release Notes)
- www.securityfocus.com/bid/106540 (VDB Entry, Third Party Advisory, vdb-entry)
- github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG… (Release Notes)
- access.redhat.com/errata/RHSA-2019:0237 (vendor-advisory, Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- access.redhat.com/errata/RHSA-2019:1352 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-16886?
- CVE-2018-16886 is a high-severity vulnerability in Etcd, classified under Improper Authentication. CVSS score: 8.1/10. Published 2019-01-14.
- How severe is CVE-2018-16886?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2018-16886 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.