CVE-2021-20404

Login denial via invalid cookie processing

Published Feb 11, 2021 · Updated Sep 16, 2024

Denial of service in IBM Security Verify Information Queue 1.0.6 and 1.0.7 allows remote attackers to block future logins. IBM identifies an invalid cookie value as the trigger but does not disclose the cookie, handler, or erroneous processing operation. The attacker must reach the service over a network; the reported consequence is blocked authentication rather than a full service crash.

CVSS severity5.3
Medium
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in IBM Security Verify Information Queue 1.0.6 and 1.0.7 allows remote attackers to block future logins. IBM identifies an invalid cookie value as the trigger but does not disclose the cookie, handler, or erroneous processing operation. The attacker must reach the service over a network; the reported consequence is blocked authentication rather than a full service crash.

The record

CVE
CVE-2021-20404
Published
Feb 11, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
Security Verify Information Queue
Classifications
T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=1.0.6
  2. Affected versionversion=1.0.7

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

IBM · Security Verify Information Queueversion=1.0.6; version=1.0.7

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
2.6IBMCVSS:3.0/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
2.3IBMCVSS:3.0/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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