How severe is CVE-2021-34637?

CVE-2021-34637 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-34637 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34637?

CVE-2021-34637 affects Post Index Project Post Index. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-34637?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-34637 published?

CVE-2021-34637 was published on 2021-08-02 and last updated on 2026-06-17.

CVE-2021-34637

CVE-2021-34637 is a high-severity vulnerability in Post Index Project Post Index with a CVSS 3.x base score of 8.8. 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-352.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-352
Affected product: Post Index Project Post Index
Published: 2021-08-02
Last modified: 2026-06-17

Description

The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.

Frequently asked questions

What is CVE-2021-34637?: The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.
How severe is CVE-2021-34637?: CVE-2021-34637 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-34637 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34637?: CVE-2021-34637 affects Post Index Project Post Index. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-34637?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-34637 published?: CVE-2021-34637 was published on 2021-08-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:post_index_project:post_index:*:*:*:*:*:wordpress:*:*

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