CVE-2021-20479Network attack vector

Sensitive-data decryption via weak cryptographic algorithms

Published May 9, 2022 · Updated Sep 17, 2024

Weak cryptography in IBM Cloud Pak System 2.3.0 through 2.3.3.3 Interim Fix 1 allows remote attackers to decrypt sensitive data. The product protects highly sensitive information with weaker-than-expected algorithms, but IBM has not disclosed the algorithms, component, or cryptographic operation. Exploitation is network-based and unauthenticated but requires high complexity; the reported consequence is confidentiality loss without integrity or availability impact.

CVSS severity7.5
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Weak cryptography in IBM Cloud Pak System 2.3.0 through 2.3.3.3 Interim Fix 1 allows remote attackers to decrypt sensitive data. The product protects highly sensitive information with weaker-than-expected algorithms, but IBM has not disclosed the algorithms, component, or cryptographic operation. Exploitation is network-based and unauthenticated but requires high complexity; the reported consequence is confidentiality loss without integrity or availability impact.

The record

CVE
CVE-2021-20479
Published
May 9, 2022
Updated
Sep 17, 2024
Vendor
IBM
Product
Cloud Pak System
Classifications
CWE-327
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 9, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=2.3.0
  2. Affected versionversion=2.3.3.3.Interim.Fix1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · Cloud Pak Systemversion=2.3.0; version=2.3.3.3.Interim.Fix1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9IBM PSIRTCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
5.2IBM PSIRTCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

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-327Use of a Broken or Risky Cryptographic Algorithm

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo