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Db2Application · Ibm

CVE-2021-29763

MEDIUM · 5.1 CVSS v3.1 Published 2021-09-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
56/100
Remediation priority · Elevated
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
IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 11.1 and 11.5 under very specific conditions, could allow a local user to keep running a procedure that could cause the system to run out of memory.and cause a denial of service. IBM X-Force ID: 202267.

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 confidence

IBM Db2 versions 11.1 and 11.5 contain a vulnerability where a local user can exploit a flaw allowing them to keep a procedure running continuously under very specific conditions, resulting in memory exhaustion and denial of service. The attack requires local access and targets the procedure execution mechanism.

MitigationApply IBM's published patches for CVE-2021-29763. Until patched, restrict local database user privileges and monitor system memory usage for anomalous sustained consumption by Db2 processes.

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
Affected:= 11.1= 11.5

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

CVSS:3.1/AV:L/AC:H/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. Determine installed Db2 version
    Run command: `db2level` or query `SELECT SERVICE_LEVEL FROM SYSIBMADM.DBMCONFIG`
    Affected if Version is exactly 11.1 or exactly 11.5 (these are the only affected versions)
  2. Identify unusually long-running procedure executions
    Query system catalog: `SELECT AGENT_ID, STMT_TEXT, ELAPSED_TIME_SEC FROM SYSIBMADM.MONITOR_ACTIVITIES WHERE ACTIVITY_STATE = 'EXECUTING' AND ELAPSED_TIME_SEC > threshold` (compare against normal baseline for your environment)
    Affected if Procedures remain in EXECUTING state for abnormally long durations without completing
  3. Monitor Db2 process memory consumption
    Use OS-level tools (top, ps, task manager) to monitor memory usage of db2sysc and related Db2 processes over time
    Affected if Memory usage of Db2 processes grows continuously without stabilizing or releasing
  4. Verify local database user access exists
    Query `SELECT GRANTEE, AUTHIDTYPE FROM SYSCAT.DBAUTH` to identify local database users; check OS-level user membership
    Affected if Untrusted local users have CONNECT privilege on any database (enables the attack vector)

You are affected only if you have Db2 version 11.1 or 11.5 AND observe procedures executing continuously with unbounded memory growth from a local database user context.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply IBM's published patches for CVE-2021-29763. Until patched, restrict local database user privileges and monitor system memory usage for anomalous sustained consumption by Db2 processes.

Recommended fix Moderate confidence

Db2 11.5.9 or later (or latest 11.1 fix pack with APAR installation)

  1. 1. Identify current Db2 version by running: db2pd -dbptyping | head -5 or checking db2level output
  2. 2. Download the latest available fix pack for your Db2 edition (11.1 or 11.5) from IBM Fix Central (https://www.ibm.com/support/fixcentral/)
  3. 3. Stop all Db2 instances and dependencies: db2stop force (run as db2 instance owner)
  4. 4. Install the fix pack as the root user using: db2updpf -l <logfile>
  5. 5. After installation, update the database manager configuration: db2updt -d <database_name>
  6. 6. Restart Db2 instances: db2start
  7. 7. Verify the fix is applied by checking: db2level and confirming the version includes the security fix
Caveat Verify application compatibility with new fix pack in non-production environment before deploying; some deprecated features may exist in newer fix packs

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

Fix this in Db2 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing6.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,320
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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-2021-29763 in production — separate from our analysis above.

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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