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Fencer Vulns
high 8.8

CVE-2021-32739 json

Results of queries for ApiListener objects include the ticket salt which allows in turn to steal (more privileged) identities

published 2021-07-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19513

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

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.

Patch / fix

  • icinga icinga 2.11.10, 2.12.5
  • icinga2 Debian 14, Debian 13, Debian 12 2.12.5-1

debian advisories DEBIAN-CVE-2021-32739

  • icinga2 openSUSE Tumbleweed 2.13.1-1.3
  • icinga2 Package Hub 15 SP3, Package Hub 15 SP2, Package Hub 15 SP1 +2 more 2.12.5-bp153.2.5.1

opensuse advisories openSUSE-SU-2024:10856-1openSUSE-SU-2021:1089-1

Exploit prediction

1.14% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Icinga/icinga2/security/advisories/GHSA-98wp-jc6q-x5q5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

  • Icinga icinga2

Classification

Weakness
  • CWE-267 Privilege Defined With Unsafe Actions
  • CWE-269 Improper Privilege Management

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.