CVE-2021-23053Network attack vector

Disk-space exhaustion via unbounded brute-force records

Published Sep 14, 2021 · Updated Aug 3, 2024

Uncontrolled resource consumption in F5 BIG-IP Advanced WAF and ASM allows remote attackers to exhaust MySQL disk space. Undisclosed MySQL tables used by brute force protection accept rows without a limit, allowing attack traffic to consume the database volume. The condition requires brute force protection on a virtual server and sustained brute force traffic; exhaustion degrades availability without reported data disclosure or modification.

CVSS severity5.3
Medium
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in F5 BIG-IP Advanced WAF and ASM allows remote attackers to exhaust MySQL disk space. Undisclosed MySQL tables used by brute force protection accept rows without a limit, allowing attack traffic to consume the database volume. The condition requires brute force protection on a virtual server and sustained brute force traffic; exhaustion degrades availability without reported data disclosure or modification.

The record

CVE
CVE-2021-23053
Published
Sep 14, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, CWE-770, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
4.3NIST NVDAV:N/AC:M/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.

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-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
T1499.003Application Exhaustion Flood

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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