Vulnerability in Icinga (CVE-2021-32739)

Summary

Vulnerability in Icinga (CVE-2021-32739). Successful exploitation can lead to full system takeover. Exploitable via ticket_salt.

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2021-32739 has been found in Icinga.
Attackers can target a specific entry point like ticket_salt over the network to misuse the product.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Icinga CVE-2021-32739" on the vendor's site.

CVE-2021-32739 (Icinga)
Attack vector: remote (network-reachable) / no user interaction
Attack surface: ticket_salt / ApiListener
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Icinga. Attackers reach the vulnerable code path via ticket_salt.

📍 Affected scope

Check the vendor advisory for the affected versions of Icinga. Attack surface: ticket_salt / ApiListener.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Icinga' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Icinga' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Icinga を grep し、稼働しているサービス・バージョンを把握する。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Fix status by distribution

Fixed packages published by each distribution for this CVE

Ubuntu UBUNTU-CVE-2021-32739 icinga2

References

advisory icinga.com
advisory lists.debian.org
report github.com
web lists.debian.org