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CVE-2016-2785: Puppet: Improper Access Control

CVE-2016-2785 is rated critical with a CVSS v3.1 base score of 9.8 and affects Puppet. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

Puppet Server before 2.3.2 and Ruby puppetmaster in Puppet 4.x before 4.4.2 and in Puppet Agent before 1.4.2 might allow remote attackers to bypass intended auth.conf access restrictions by leveraging incorrect URL decoding.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-284: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected products

• Puppet: 4.0.0; 4.0.0 rc1; 4.0.0 rc2; 4.0.0 rc3; 4.1.0; 4.2.0; 4.2.1; 4.2.2; 4.2.3; 4.3.0; 4.3.1; 4.3.2
• Puppet Server: 2.0.0; 2.1.0; 2.1.1; 2.1.2; 2.2.0; 2.3.0; 2.3.1
• Puppet Agent: 1.4.1

References

• https://github.com/puppetlabs/puppet/pull/4921/commits/8d2ce797db265720f0a20d1d46ee2757b4e4f6b2
• https://puppet.com/security/cve/cve-2016-2785
• https://security.gentoo.org/glsa/201606-02