dbcve.org
Debian LinuxOperating system · Debian

CVE-2019-15941

CRITICAL · 9.8 CVSS v3.1 Published 2019-09-25
Fix available
A fix is available. Upgrade to after 2.0.5 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
OpenID Connect Issuer in LemonLDAP::NG 2.x through 2.0.5 may allow an attacker to bypass access control rules via a crafted OpenID Connect authorization request. To be vulnerable, there must exist an OIDC Relaying party within the LemonLDAP configuration with weaker access control rules than the target RP, and no filtering on redirection URIs.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The OpenID Connect Issuer in LemonLDAP::NG versions 2.x through 2.0.5 contains a vulnerability allowing attackers to bypass access control rules via crafted OIDC authorization requests. The attack requires existence of an OIDC Relaying Party with weaker access control rules than the target RP and absence of redirection URI filtering, enabling unauthorized access to protected resources.

MitigationUpgrade LemonLDAP::NG to version 2.0.6 or later to patch the vulnerability. Additionally, enforce strict access control rules across all OIDC RPs and implement URI allowlist filtering on redirect URLs to prevent exploitation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Debian LinuxOperating system
Affected:= 10.0
Lemonldap\Application
Affected:>= 2.0.0, <= 2.0.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify LemonLDAP::NG version
    Check the installed package version via package manager (dpkg -l lemonldap-ng-core or apt list installed) or access the LemonLDAP::NG manager web interface and look at the version displayed in the footer or about page
    Affected if version is 2.0.5 or earlier (2.0.0 through 2.0.5 inclusive)
  2. Confirm OpenID Connect Issuer is enabled
    Examine the LemonLDAP::NG configuration files (lemonldap-ng.ini or llconf) or access the manager web interface and navigate to OIDC Issuer parameters to verify OIDC is configured and active
    Affected if OIDC Issuer module is configured and active
  3. Identify OIDC Relaying Party configurations
    Review the OIDC Relaying Party (RP) settings in the LemonLDAP::NG manager under the OpenID Connect service provider configuration, noting each RP and its associated access control rules
    Affected if multiple OIDC RPs exist with differing access control rule sets
  4. Inspect redirect URI filtering settings
    Examine each OIDC RP configuration to check if redirect_uri validation uses an allowlist or strict URI matching, looking for parameters like redirect_uri_validation or trusted_uri in the RP configuration
    Affected if redirect URI filtering is absent or uses overly permissive patterns that could allow URI manipulation

User is affected if LemonLDAP::NG version is 2.0.0-2.0.5, OpenID Connect is enabled, and there exists an OIDC RP with weaker access controls alongside absent or weak redirect URI filtering that could enable authorization request manipulation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 2.0.5
Interim mitigation

Upgrade LemonLDAP::NG to version 2.0.6 or later to patch the vulnerability. Additionally, enforce strict access control rules across all OIDC RPs and implement URI allowlist filtering on redirect URLs to prevent exploitation.

Recommended fix High confidence

LemonLDAP::NG 2.0.6 or later (latest stable 2.0.x release)

  1. Upgrade LemonLDAP::NG from version 2.0.0-2.0.5 to version 2.0.6 or later
  2. Verify the upgrade was successful by checking the installed version
  3. Test that OpenID Connect authorization requests properly enforce access control rules
  4. Ensure all OIDC Relaying Parties have appropriate access control rules configured

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-15941 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-15941 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data