How severe is CVE-2021-22158?

CVE-2021-22158 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-22158 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22158?

CVE-2021-22158 affects Proofpoint Insider Threat Management. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-22158?

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-2021-22158 published?

CVE-2021-22158 was published on 2021-04-06 and last updated on 2026-06-17.

CVE-2021-22158

CVE-2021-22158 is a high-severity vulnerability in Proofpoint Insider Threat Management with a CVSS 3.x base score of 7.2. 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-611.

Key facts

Severity: High (CVSS 3.x base score 7.2)
CVSS v2: 6.5
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-611
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 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.

Frequently asked questions

What is 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.
How severe is CVE-2021-22158?: CVE-2021-22158 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-22158 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22158?: CVE-2021-22158 affects Proofpoint Insider Threat Management. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-22158?: 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-2021-22158 published?: CVE-2021-22158 was published on 2021-04-06 and last updated on 2026-06-17.

References

https://www.proofpoint.com/us/security/security-advisories/pfpt-sa-2021-0003

Affected products (1)

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

More vulnerabilities in Proofpoint Insider Threat Management

CVE-2020-8884 — High (CVSS 8.8): rcdsvc in the Proofpoint Insider Threat Management Windows Agent (formerly ObserveIT Windows Agent) before 7.9 allows…
CVE-2021-27900 — High (CVSS 8.1): The Proofpoint Insider Threat Management Server (formerly ObserveIT Server) is missing an authorization check on…
CVE-2022-25294 — High (CVSS 7.8): Proofpoint Insider Threat Management Agent for Windows relies on an inherently dangerous function that could enable an…
CVE-2021-22159 — High (CVSS 7.8): Insider Threat Management Windows Agent Local Privilege Escalation Vulnerability The Proofpoint Insider Threat…
CVE-2023-4801 — High (CVSS 7.5): An improper certification validation vulnerability in the Insider Threat Management (ITM) Agent for MacOS could be used…
CVE-2021-27899 — High (CVSS 7.4): The Proofpoint Insider Threat Management Agents (formerly ObserveIT Agent) for MacOS and Linux perform improper…

All CVEs affecting Proofpoint Insider Threat Management →

Other CWE-611 (Improper Restriction of XML External Entity Reference (XXE)) vulnerabilities

CVE-2022-22486 — Critical (CVSS 10.0): IBM Tivoli Workload Scheduler 9.4, 9.5, and 10.1 is vulnerable to an XML External Entity Injection (XXE) attack when…
CVE-2019-14678 — Critical (CVSS 10.0): SAS XML Mapper 9.45 has an XML External Entity (XXE) vulnerability that can be leveraged by malicious attackers in…
CVE-2015-9280 — Critical (CVSS 10.0): MailEnable before 8.60 allows XXE via an XML document in the request.aspx Options parameter.
CVE-2018-1000838 — Critical (CVSS 10.0): autopsy version <= 4.9.0 contains a XML External Entity (XXE) vulnerability in CaseMetadata XML Parser that can result…
CVE-2018-1000837 — Critical (CVSS 10.0): UML Designer version <= 8.0.0 contains a XML External Entity (XXE) vulnerability in XML parser for plugins that can…
CVE-2018-1000835 — Critical (CVSS 10.0): KeePassDX version <= 2.5.0.0beta17 contains a XML External Entity (XXE) vulnerability in kdbx file parser that can…

Browse all CWE-611 (Improper Restriction of XML External Entity Reference (XXE)) vulnerabilities →