Critical, CVSS 9.0GoAmendedPublished
Canonical ADSys Uses a Less Trusted Source
CVE-2026-12249 · GHSA-crm4-q7v4-c2r2
- Affected
- Go github.com/ubuntu/adsys < 0.16.3-0.20250318112551-8b1939f96d38
- Fixed in
- 0.16.3-0.20250318112551-8b1939f96d38· Vendor fix available
- Issue
- An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendorsamba/gp/gpcertautoenrollext.py), ADSys utilizes a plaintext HTTP connection (http://) instead of a secure HTTPS connection (https://) to request the CA certificate from the Active Directory Certificate Services server (GetCACert). An unauthenticated network attacker positioned between the managed Ubuntu host and the configured AD CS CA hostname can conduct a Man-in-the-Middle (MITM) attack. By intercepting the plaintext HTTP request, the attacker can supply an arbitrary, attacker-controlled Root CA certificate. Because the system automatically accepts this certificate and registers it into the local system trust store via update-ca-certificates, this results in system-wide trust store poisoning. Consequently, TLS clients utilizing the operating…
Recommended action: Upgrade to 0.16.3-0.20250318112551-8b1939f96d38 (pre-release) or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.