Db2Application · Ibm
CVE-2025-1000
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 · uneditedIBM Db2 for Linux, UNIX and Windows (includes DB2 Connect Server) 11.5.0 through 11.5.9 and 12.1.0 through 12.1.1 could allow an authenticated user to cause a denial of service when connecting to a z/OS database due to improper handling of automatic client rerouting.
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 · moderate confidenceIBM Db2 for Linux, UNIX, and Windows versions 11.5.0-11.5.9 and 12.1.0-12.1.1 contain a vulnerability in the automatic client rerouting feature when connecting to z/OS databases. An authenticated user can exploit improper handling of client rerouting requests to trigger a denial of service condition on the database server.
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
Db2Application
>= 11.5, <= 11.5.9>= 12.1.0, <= 12.1.1CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed Db2 versionRun 'db2level' command or query DB2 version via 'SELECT service_level FROM sysibmadm.env_inst_info'Affected if Version is 11.5.0 through 11.5.9 OR 12.1.0 through 12.1.1
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Confirm automatic client rerouting is configuredCheck Db2 client configuration for AUTOMATIC_CLIENT_REROUTE settings in db2cli.ini or database manager configuration (DMC) using 'GET DB CFG FOR <database>' and look for AUTOMATIC_CLIENT_REROUTE parameterAffected if AUTOMATIC_CLIENT_REROUTE is set to ON or YES for any database connecting to z/OS
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Check for z/OS database connectionsReview client connection settings or catalog entries for z/OS databases using 'LIST NODE DIRECTORY' and 'LIST DATABASE DIRECTORY' commands, or check DDF (Distributed Data Facility) configurationAffected if Any database connection profile targets a z/OS subsystem or remote Db2 on z/OS
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Verify authenticated user access to rerouting featureReview Db2 instance audit logs or security traces for client rerouting request patterns using 'db2audit' or examine connection attempt logs for reroute requestsAffected if Application or user accounts have connectivity that triggers automatic client rerouting to z/OS databases
You are affected if your Db2 version falls within 11.5.0-11.5.9 or 12.1.1 and automatic client rerouting is enabled for connections to z/OS databases.
Generated from the published advisory. Verify against your own configuration.
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 dataApply IBM's patch for this vulnerability or upgrade to a Db2 version beyond the affected ranges (11.5.9 and 12.1.1). If immediate patching is not feasible, consider disabling or restricting automatic client rerouting for z/OS connections as a compensating control.
Fix this in Db2
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-1000 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-1000 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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