CVE-2021-37223Network attack vector

Authenticated internal access via unsanitized report URLs

Published Oct 5, 2021 · Updated Jul 9, 2026

SSRF in schedulereport.php in Nagios XI 5.8.4 and earlier allows remote authenticated users to access internal resources or read local files. The scheduled-report handler accepts an attacker-controlled target page without sanitization and fetches it while generating a PDF screenshot. Any authenticated account can reach the feature, and the resulting report exposes internal responses or local system-file contents.

CVSS severity6.5
Medium
EPSS probability4.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in schedulereport.php in Nagios XI 5.8.4 and earlier allows remote authenticated users to access internal resources or read local files. The scheduled-report handler accepts an attacker-controlled target page without sanitization and fetches it while generating a PDF screenshot. Any authenticated account can reach the feature, and the resulting report exposes internal responses or local system-file contents.

The record

CVE
CVE-2021-37223
Published
Oct 5, 2021
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-918, CAPEC-664
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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