CVE-2023-33850Network attack vector

Sensitive-information disclosure via RSA decryption timing oracle

Published Aug 22, 2023 · Updated Nov 3, 2025

Timing side channel in IBM GSKit-Crypto in affected CICS TX and TXSeries releases allows remote attackers to obtain sensitive information. The RSA decryption implementation exposes input-dependent timing differences while processing an excessive sequence of attacker-chosen ciphertexts. Unauthenticated network access and many decryption trials are required, and the reported consequence is confidentiality loss only.

CVSS severity7.5
High
EPSS probability1.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in IBM GSKit-Crypto in affected CICS TX and TXSeries releases allows remote attackers to obtain sensitive information. The RSA decryption implementation exposes input-dependent timing differences while processing an excessive sequence of attacker-chosen ciphertexts. Unauthenticated network access and many decryption trials are required, and the reported consequence is confidentiality loss only.

The record

CVE
CVE-2023-33850
Published
Aug 22, 2023
Updated
Nov 3, 2025
Vendor
IBM
Product
CICS TX Standard
Classifications
CWE-203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=11.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · CICS TX Standardversion=11.1
IBM · CICS TX Advancedversion=10.1, 11.1
IBM · TXSeries for Multiplatformsversion=8.1; version=8.1, 8.2, 9.1; version=8.2; version=9.1

Published CVSS scores

7.5IBM SupportCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5IBM CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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