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.

Published: 2021-04-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27900 is rated Moderate Risk (63.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.45%). EPSS rose +2.21% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-27900

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.24% 2.45% +2.21%
2 2025-03-30 0.29% 0.24% -0.05%
3 2025-03-29 — 0.29% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27900

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.2 [email protected]
5.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 4.9 [email protected]

Weakness enumeration for CVE-2021-27900

Affected software / configurations for CVE-2021-27900

Vendor Product Version Raw CPE
proofpoint insider_threat_management >= 7.9.0, < 7.9.3 cpe:2.3:a:proofpoint:insider_threat_management:*:*:*:*:*:*:*:*
proofpoint insider_threat_management >= 7.10.0, < 7.10.3 cpe:2.3:a:proofpoint:insider_threat_management:*:*:*:*:*:*:*:*
proofpoint insider_threat_management >= 7.11.0, < 7.11.1 cpe:2.3:a:proofpoint:insider_threat_management:*:*:*:*:*:*:*:*

References for CVE-2021-27900

cvelogic Threat Intelligence