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CVE Record

CVE-2020-27836: A flaw was found in cluster-ingress-operator.

A flaw was found in cluster-ingress-operator. A change to how the router-default service allows only certain IP source ranges could allow an attacker to access resources that would otherwise be restricted to specified IP ranges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability..

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw could let traffic reach OpenShift ingress resources that administrators intended to limit to specific IP ranges. If those source-range controls protect sensitive services, the issue can weaken a key access boundary. The source bundle names a fixed cluster-ingress-operator container build, but provides limited severity detail.

Executive priority

Prioritize remediation for clusters where IP source ranges are used to protect sensitive or administrative workloads. Without active-exploitation evidence or CVSS data, this is not automatically emergency-class, but it is a meaningful access-control risk.

Technical view

CVE-2020-27836 is a CWE-732 issue in cluster-ingress-operator involving router-default service source range handling. A change to allowed IP source ranges could allow access to resources that should be restricted. Red Hat identifies a fixed build: ose-cluster-ingress-operator-container-v4.6.0-202012161211.p0.

Likely exposure

Exposure is most relevant where affected cluster-ingress-operator versions manage router-default service IP source range restrictions. Organizations not relying on those restrictions may have lower practical impact, but the bundle does not provide complete affected-version boundaries.

Exploitation context

The source bundle does not show CISA KEV listing or public evidence of active exploitation. It describes a potential access-control bypass affecting confidentiality, integrity, and availability. Treat exploitation status as unconfirmed, not actively exploited.

Researcher notes

Available evidence is sparse: no CVSS vector, no detailed affected-version matrix, and no confirmed exploitation in the bundle. Focus analysis on Red Hat advisories, the Bugzilla entries, and the referenced OpenShift commit before making broad exposure claims.

Mitigation direction

  • Check Red Hat guidance for applicable OpenShift and operator versions.
  • Upgrade to ose-cluster-ingress-operator-container-v4.6.0-202012161211.p0 or a later fixed build if applicable.
  • Review router-default source range restrictions for sensitive routes.
  • Use independent network controls where ingress source filtering protects critical services.

Validation and detection

  • Inventory cluster-ingress-operator container versions across clusters.
  • Confirm router-default service source range settings match intended allowlists.
  • Verify restricted resources are not reachable outside approved source ranges.
  • Review ingress and service access logs for unexpected source networks.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-732: Authorization and privilege behavior lookup

Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2020-27836 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/acluster-ingress-operatorFixed in ose-cluster-ingress-operator-container-v4.6.0-202012161211.p0.Listed
Weakness

CWE details

CWE-732

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-732 · source CWE mapping

Incorrect Permission Assignment for Critical Resource

Incorrect Permission Assignment for Critical Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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