GraylogApplication

CVE-2020-15813

HIGH · 8.1 CVSS v3.1 Published 2020-07-17
Fix available
A fix is available. Upgrade to 3.3.3 or later.
See remediation →
90/100
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
Graylog before 3.3.3 lacks SSL Certificate Validation for LDAP servers. It allows use of an external user/group database stored in LDAP. The connection configuration allows the usage of unencrypted, SSL- or TLS-secured connections. Unfortunately, the Graylog client code (in all versions that support LDAP) does not implement proper certificate validation (regardless of whether the "Allow self-signed certificates" option is used). Therefore, any attacker with the ability to intercept network traffic between a Graylog server and an LDAP server is able to redirect traffic to a different LDAP server (unnoticed by the Graylog server due to the lack of certificate validation), effectively bypassing Graylog's authentication mechanism.

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

Graylog before version 3.3.3 does not validate SSL certificates when connecting to LDAP servers for external authentication. The LDAP client code in all affected versions fails to implement proper certificate validation regardless of the 'Allow self-signed certificates' setting. An attacker with network interception capability can perform a man-in-the-middle attack, redirecting LDAP traffic to a malicious server and bypassing Graylog's authentication mechanism.

MitigationUpgrade Graylog to version 3.3.3 or later where proper SSL certificate validation is implemented. Until upgraded, ensure LDAP servers are on trusted networks and consider network-level protections against MITM attacks.

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
GraylogApplication
Affected:< 3.3.3

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/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 installed Graylog version
    Run 'graylog-ctl version' or check the Graylog web interface under System > Nodes. Alternatively, check the RPM/DEB package with 'rpm -q graylog-enterprise' or 'dpkg -l graylog-enterprise'.
    Affected if The installed version is any release before 3.3.3 (e.g., 3.3.2, 3.3.1, 3.3.0, 3.2.x, 3.1.x, etc.)
  2. Determine if LDAP authentication is configured
    Navigate to System > Authentication in the Graylog web interface, or inspect the server.conf file for 'ldap' settings under the 'authentication' section. Look for enabled LDAP realms.
    Affected if LDAP authentication is actively configured or enabled in Graylog regardless of the 'Allow self-signed certificates' setting
  3. Verify LDAP connection uses SSL/TLS
    In the Graylog web interface under System > Authentication > LDAP, examine the LDAP server configuration. Check if the server URL uses 'ldaps://' or port 636 (LDAPS), or if TLS is enabled on the standard LDAP port.
    Affected if LDAP connections are configured to use SSL/TLS (ldaps://) or STARTTLS, which relies on the faulty certificate validation
  4. Confirm certificate validation behavior
    Note that the vulnerability exists regardless of the 'Allow self-signed certificates' checkbox state in the LDAP configuration. This setting does not provide protection for this specific flaw.
    Affected if The 'Allow self-signed certificates' setting is toggled in any position - the flaw is present regardless of this configuration

A user is affected if they run any Graylog version prior to 3.3.3 AND have LDAP authentication configured, regardless of SSL certificate settings.

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.

From vendor data
Upgrade available Upgrade to 3.3.3 or later
Fixed in 3.3.3
Interim mitigation

Upgrade Graylog to version 3.3.3 or later where proper SSL certificate validation is implemented. Until upgraded, ensure LDAP servers are on trusted networks and consider network-level protections against MITM attacks.

Fix this in Graylog Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,970
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,152.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-15813 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2020-15813 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