ZeekApplication

CVE-2019-12175

HIGH · 7.5 CVSS v3.0 Published 2019-07-17
Fix available
A fix is available. Upgrade to 2.6.2 or later.
See remediation →
84/100
Remediation priority · High
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
In Zeek Network Security Monitor (formerly known as Bro) before 2.6.2, a NULL pointer dereference in the Kerberos (aka KRB) protocol parser leads to DoS because a case-type index is mishandled.

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

In Zeek Network Security Monitor before version 2.6.2, the Kerberos protocol parser contains a NULL pointer dereference vulnerability caused by mishandling a case-type index. When processing certain KRB traffic, the parser incorrectly handles an index value, resulting in a NULL pointer dereference that causes the security monitor to crash, leading to denial of service.

MitigationUpdate Zeek Network Security Monitor to version 2.6.2 or later to patch the NULL pointer dereference in the KRB protocol parser. If immediate patching is not possible, consider filtering or rate-limiting suspicious KRB traffic as a temporary workaround.

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
ZeekApplication
Affected:< 2.6.2

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
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Check if Zeek is installed and get version
    Run `zeek --version` or `bro --version` in the terminal to determine the installed Zeek/Bro version.
    Affected if The version output is lower than 2.6.2 (e.g., 2.6.1, 2.6.0, or earlier)
  2. Verify Kerberos logging is enabled
    Check if the `krb.log` file is being generated in your Zeek log directory (typically `/var/log/zeek/` or `./logs/`). This indicates the KRB analyzer is active.
    Affected if KRB logging is active and the Zeek version is below 2.6.2
  3. Confirm KRB protocol analyzer is loaded
    Inspect your Zeek `loaded_scripts.log` or run `zeek -N | grep -i krb` to see if the Kerberos analyzer script is loaded.
    Affected if The KRB analyzer is loaded and the Zeek version is below 2.6.2
  4. Check if KRB traffic is being processed
    Review network traffic captures or Zeek notice logs for any Kerberos traffic being parsed by Zeek. Presence of KRB traffic processed by Zeek confirms the vulnerable code path is reachable.
    Affected if Zeek is processing KRB traffic and the version is below 2.6.2

You are affected if Zeek version is below 2.6.2 AND the Kerberos protocol analyzer is actively processing KRB traffic on your monitored network.

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 2.6.2 or later
Fixed in 2.6.2
Interim mitigation

Update Zeek Network Security Monitor to version 2.6.2 or later to patch the NULL pointer dereference in the KRB protocol parser. If immediate patching is not possible, consider filtering or rate-limiting suspicious KRB traffic as a temporary workaround.

Fix this in Zeek Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,340
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Scan for this in your stack

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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-2019-12175 in production — separate from our analysis above.

No notes yet

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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