CVE-2021-32739Public exploitNetwork attack vector

Identity theft via exposed PKI ticket salt

Published Jul 15, 2021 · Updated Nov 3, 2025

Privilege escalation in Icinga 2 2.4.0 through 2.12.4 allows remote authenticated users to assume other identities through the API. The ApiListener object query returns ticket_salt to read-only API users, who can derive valid PKI tickets for arbitrary certificate common names. Access requires objects/query/ApiListener permission or an equivalent wildcard; forged certificates can impersonate API users or cluster nodes.

CVSS severity8.8
High
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Icinga 2 2.4.0 through 2.12.4 allows remote authenticated users to assume other identities through the API. The ApiListener object query returns ticket_salt to read-only API users, who can derive valid PKI tickets for arbitrary certificate common names. Access requires objects/query/ApiListener permission or an equivalent wildcard; forged certificates can impersonate API users or cluster nodes.

The record

CVE
CVE-2021-32739
Published
Jul 15, 2021
Updated
Nov 3, 2025
Vendor
Icinga
Product
Icinga 2
Classifications
CWE-267, CWE-269, T1649
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.4.0, <= 2.12.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Icinga · Icinga 2version=>= 2.4.0, <= 2.12.4

Published CVSS scores

8.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:S/C:P/I:P/A:P

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 exploitPublished

Weakness, pattern, technique

CWE-267Privilege Defined With Unsafe Actions
CWE-269Improper Privilege Management
T1649Steal or Forge Authentication Certificates

Public exploit references

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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