How severe is CVE-2021-27900?

CVE-2021-27900 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-27900 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27900?

CVE-2021-27900 affects Proofpoint Insider Threat Management. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27900?

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-2021-27900 published?

CVE-2021-27900 was published on 2021-04-06 and last updated on 2026-06-17.

CVE-2021-27900

CVE-2021-27900 is a high-severity vulnerability in Proofpoint Insider Threat Management with a CVSS 3.x base score of 8.1. 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-862.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 5.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Proofpoint Insider Threat Management
Published: 2021-04-06
Last modified: 2026-06-17

Description

The Proofpoint Insider Threat Management Server (formerly ObserveIT Server) is missing an authorization check on several pages in the Web Console. This enables a view-only user to change any configuration setting and delete any registered agents. All versions before 7.11.1 are affected.

Frequently asked questions

What is CVE-2021-27900?: The Proofpoint Insider Threat Management Server (formerly ObserveIT Server) is missing an authorization check on several pages in the Web Console. This enables a view-only user to change any configuration setting and delete any registered agents. All versions before 7.11.1 are affected.
How severe is CVE-2021-27900?: CVE-2021-27900 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-27900 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27900?: CVE-2021-27900 affects Proofpoint Insider Threat Management. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27900?: 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-2021-27900 published?: CVE-2021-27900 was published on 2021-04-06 and last updated on 2026-06-17.

References

https://www.proofpoint.com/us/security/security-advisories/pfpt-sa-2021-0005

Affected products (1)

cpe:2.3:a:proofpoint:insider_threat_management:*:*:*:*:*:*:*:*

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