BlackTreeCVE Intelligence
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Full vulnerability report · 2019
CVE-2019-9901High confidence

A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin

Unknown · Unknown

6.5MediumCVSS 3.0
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 4.95% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Open-source package ranges2 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
Gogithub.com/envoyproxy/envoySEMVER: introduced 0; fixed 1.9.11.9.1OSV record ↗aggregator derived · 10 Sep 2026
gogithub.com/envoyproxy/envoy<= 1.9.01.9.1GitHub advisory ↗github reviewed aggregator · 24 Aug 2023
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-2065

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available
01

What, why and how

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

What

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Use of Incorrectly-Resolved Name or Reference → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-706 ↗

CWE-706: Use of Incorrectly-Resolved Name or Reference. The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.0/AC:H/AV:N/A:L/C:L/I:L/PR:N/S:C/UI:N

Common Vulnerability Scoring System 3.0: the compact vector below is decoded into plain language.

ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.AVNetworkAttack vector: The vulnerable component can be reached over a network.ALowAvailability impact: A successful attack can cause a limited loss.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.PRNonePrivileges required: The attacker does not need an account or existing privileges.SChangedScope: The attack can affect a component governed by a different security authority.UINoneUser interaction: No action by another user is required.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-706
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

JVN iPedia · Japanese · JVNDB-2019-004240Envoy における誤って解決された名前や参照の使用に関する脆弱性

Envoy には、誤って解決された名前や参照の使用に関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
n/a
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 25 Apr 2019 · Last source change 4 Aug 2024, 22:01 UTC · CWE-706 · Use of Incorrectly-Resolved Name or Reference

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2022-2065
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2022-2065 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2022-2065"}
    ENISA EUVD ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: added mitigation: github.com/6435; added remediation: github.com/6435; 1 further additions.
    Before
    no authoritative guidance recorded
    After
    mitigation: github.com/6435 · remediation: github.com/6435 · vendor advisory: envoyproxy.io/version_history
    github.com ↗
  3. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    github.com ↗
  4. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Mitigation reference recorded
ENISA EUVD · EUVD-2022-2065↗CVE authority or vendor reference↗Mitigation reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2019-9901 · cve.blacktree.nl