CVE-2021-32739
CVSS v3
8.8
HIGH
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. From version 2.4.0 through version 2.12.4, a vulnerability exists that may allow privilege escalation for authenticated API users. With a read-ony user's credentials, an attacker can view most attributes of all config objects including `ticket_salt` of `ApiListener`. This salt is enough to compute a ticket for every possible common name (CN). A ticket, the master node's certificate, and a self-signed certificate are enough to successfully request the desired certificate from Icinga. That certificate may in turn be used to steal an endpoint or API user's identity. Versions 2.12.5 and 2.11.10 both contain a fix the vulnerability. As a workaround, one may either specify queryable types explicitly or filter out ApiListener objects.
Technical details
- Published
- 2021-07-15
Frequently asked questions
What is CVE-2021-32739?
Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. From version 2.4.0 through version 2.12.4, a vulnerability exists that may allow privilege escalation for authenticated API users. With a read-ony user's credentials, an attacker can view most attributes of all config objects including `ticket_salt` of `ApiListener`. This salt is enough to compute a ticket for every possible common name (CN). A ticket, the master node's certificate, and a self-signed certificate are enough to successfully request the desired certificate from Icinga. That certificate may in turn be used to steal an endpoint or API user's identity. Versions 2.12.5 and 2.11.10 both contain a fix the vulnerability. As a workaround, one may either specify queryable types explicitly or filter out ApiListener objects.
Is CVE-2021-32739 actively exploited?
Active exploitation of CVE-2021-32739 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-32739?
CVE-2021-32739 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2021-32739 affecting your environment?
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