CVE-2021-20576Network attack vector

Unauthenticated application crash via crafted HTTP GET

Published May 31, 2021 · Updated Sep 16, 2024

Denial of service in IBM Security Verify Access 20.07 allows remote attackers to crash the application with a crafted HTTP GET request. IBM identifies IBM Application Gateway as the affected component but does not disclose the request endpoint, malformed field, or code path that mishandles the request. No authentication or user interaction is required, and the documented consequence is an application crash rather than data disclosure or modification.

CVSS severity7.5
High
EPSS probability2.48%
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 Access 20.07 allows remote attackers to crash the application with a crafted HTTP GET request. IBM identifies IBM Application Gateway as the affected component but does not disclose the request endpoint, malformed field, or code path that mishandles the request. No authentication or user interaction is required, and the documented consequence is an application crash rather than data disclosure or modification.

The record

CVE
CVE-2021-20576
Published
May 31, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM Security Verify Access
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 31, 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?

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  1. Affected versionversion=20.07

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · IBM Security Verify Accessversion=20.07

Published CVSS scores

7.5IBM CorporationCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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.

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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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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