CyberSecBulletin
CVE-2023-33850NVD status: Modified

TXSeries for Multiplatforms: Observable Discrepancy

Published Updated By the CyberSecBulletin desk

CVE-2023-33850 is a high-severity observable discrepancy vulnerability in TXSeries for Multiplatforms from IBM, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected TXSeries for Multiplatforms versions: 8.1, 8.2, 9.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.17% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of TXSeries for Multiplatforms you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on ibm.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
IBMTXSeries for Multiplatforms8.1, 8.2, 9.1Not stated
IBMCICS TX Standard11.1Not stated
IBMCICS TX Advanced10.1, 11.1Not stated
IBMtxseries_for_multiplatform8.1; 8.2; 9.1Not stated
IBMcics_tx11.1; 10.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (us.ibm.com)
CVSS 3.17.5HighNVD

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Observable Discrepancy

The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Observable Discrepancy vulnerabilities (CWE-203)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in TXSeries for Multiplatforms

All TXSeries for Multiplatforms vulnerabilities

Recent Observable Discrepancy vulnerabilities

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