How severe is CVE-2021-23047?

CVE-2021-23047 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-23047 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23047?

CVE-2021-23047 affects F5 Big-ip Access Policy Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-23047?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-23047 published?

CVE-2021-23047 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2021-23047

CVE-2021-23047 is a medium-severity vulnerability in F5 Big-ip Access Policy Manager with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: F5 Big-ip Access Policy Manager
Published: 2021-09-14
Last modified: 2026-06-17

Description

On version 16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, and all versions of 13.1.x, 12.1.x and 11.6.x, when BIG-IP APM performs Online Certificate Status Protocol (OCSP) verification of a certificate that contains Authority Information Access (AIA), undisclosed requests may cause an increase in memory use. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2021-23047?: On version 16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, and all versions of 13.1.x, 12.1.x and 11.6.x, when BIG-IP APM performs Online Certificate Status Protocol (OCSP) verification of a certificate that contains Authority Information Access (AIA), undisclosed requests may cause an increase in memory use. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2021-23047?: CVE-2021-23047 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-23047 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23047?: CVE-2021-23047 affects F5 Big-ip Access Policy Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-23047?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-23047 published?: CVE-2021-23047 was published on 2021-09-14 and last updated on 2026-06-17.

References

https://support.f5.com/csp/article/K79428827

Affected products (1)

cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*

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