Txseries For MultiplatformApplication · Ibm

CVE-2023-33850

HIGH · 7.5 CVSS v3.1 Published 2023-08-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
IBM GSKit-Crypto could allow a remote attacker to obtain sensitive information, caused by a timing-based side channel in the RSA Decryption implementation. By sending an overly large number of trial messages for decryption, an attacker could exploit this vulnerability to obtain sensitive information.

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 GSKit-Crypto contains a timing-based side channel vulnerability in its RSA Decryption implementation. An attacker can exploit this by sending numerous trial decryption messages and measuring timing differences to extract sensitive information, potentially recovering plaintext or cryptographic keys.

MitigationApply the vendor patch for GSKit-Crypto when available. In the interim, implement rate limiting on decryption operations and monitor for unusual patterns of decryption requests to reduce the attack surface.

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
Txseries For MultiplatformApplication
Affected:= 8.1= 9.1= 8.2
Cics TxApplication
Affected:= 11.1= 10.1

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
None
Availability
None

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

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 IBM product
    Run product-specific command or check installed software to determine if IBM TxSeries For Multiplatform or IBM CICS TX is present. For TxSeries, use 'lslpp -l' on AIX or 'rpm -qa' on Linux. For CICS TX, check the installation directory or use product-specific commands.
    Affected if The system has IBM TxSeries For Multiplatform (versions 8.1, 8.2, or 9.1) or IBM CICS TX (versions 10.1 or 11.1) installed.
  2. Verify product version
    Check the exact version of the installed IBM product. For TxSeries, use 'lslpp -l | grep txseries' or check the version file in the installation directory. For CICS TX, use 'cicsstatus -v' or check version information in the installation path.
    Affected if The installed version matches 8.1, 8.2, or 9.1 for TxSeries, or 10.1 or 11.1 for CICS TX.
  3. Confirm GSKit-Crypto is in use
    Check if GSKit-Crypto libraries are present on the system. Look for files named 'gskit' or ' GSKit' in the product installation directories or system library paths. On AIX, check '/usr/opt/ifor/'. On Linux, check '/opt/ibm/'.
    Affected if GSKit-Crypto libraries are loaded or used by the IBM product.
  4. Determine RSA decryption usage
    Review application configuration and logs to identify if RSA decryption operations are performed. Check application configuration files for RSA key usage or TLS/SSL configuration that may trigger RSA decryption.
    Affected if The system performs RSA decryption operations using GSKit-Crypto, exposing the timing side channel.
  5. Inspect cryptographic configuration
    Examine SSL/TLS configuration files and key management settings within the IBM product. Look for cipher suites using RSA key exchange or RSA decryption in the product configuration.
    Affected if SSL/TLS or cryptographic settings enable RSA-based decryption operations.

A system is affected if it runs IBM TxSeries For Multiplatform (8.1, 8.2, or 9.1) or IBM CICS TX (10.1 or 11.1) and performs RSA decryption operations using GSKit-Crypto.

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

Apply the vendor patch for GSKit-Crypto when available. In the interim, implement rate limiting on decryption operations and monitor for unusual patterns of decryption requests to reduce the attack surface.

Fix this in Txseries For Multiplatform Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
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Scan for this in your stack

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dbcve dependency scanner

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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-2023-33850 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