CVE-2021-22158

The Proofpoint Insider Threat Management Server (formerly ObserveIT Server) is vulnerable to XML external entity (XXE) injection in the Web Console. The vulnerability requires admin user privileges and knowledge of the XML file's encryption key to successfully exploit. All versions before 7.11 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-2021-22158 is rated Moderate Risk (44.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.62%). 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-2021-22158

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 0.21% 0.62% +0.41%
2 2025-03-30 0.40% 0.21% -0.20%
3 2025-03-29 — 0.40% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22158

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
Serious risk that confidential data gets exposed in a big 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.
 1.2 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2021-22158

Affected software / configurations for CVE-2021-22158

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-2021-22158

cvelogic Threat Intelligence