CVE-2021-20337Network attack vector

Sensitive-data decryption via weak cryptography

Published Jul 26, 2021 · Updated Sep 17, 2024

Weak cryptography in IBM QRadar SIEM 7.3.0 through 7.3.3 Patch 8 and 7.4.0 through 7.4.3 GA allows attackers to decrypt sensitive data. IBM has not disclosed the affected component, algorithm, key handling, or operation that applies the weaker-than-expected cryptography. Exploitation is network-reachable and unauthenticated but requires high attack complexity under IBM's assessment; the reported consequence is decryption of highly sensitive information without modification or service interruption.

CVSS severity5.9
Medium
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Weak cryptography in IBM QRadar SIEM 7.3.0 through 7.3.3 Patch 8 and 7.4.0 through 7.4.3 GA allows attackers to decrypt sensitive data. IBM has not disclosed the affected component, algorithm, key handling, or operation that applies the weaker-than-expected cryptography. Exploitation is network-reachable and unauthenticated but requires high attack complexity under IBM's assessment; the reported consequence is decryption of highly sensitive information without modification or service interruption.

The record

CVE
CVE-2021-20337
Published
Jul 26, 2021
Updated
Sep 17, 2024
Vendor
IBM
Product
QRadar SIEM
Classifications
CWE-327
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 26, 2021CVE 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

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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=7.3.0
  2. Affected versionversion=7.3.Patch.8
  3. Affected versionversion=7.4.0
  4. Affected versionversion=7.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · QRadar SIEMversion=7.3.0; version=7.3.Patch.8; version=7.4.0; version=7.4.3

Published CVSS scores

5.9IBM CorporationCVSS: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
7.5NIST NVDCVSS: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-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

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Your stack

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