A vulnerability in the Kubernetes API server could allow an unauthenticated, remote attacker to gain elevated privileges on a targeted system.
The vulnerability is due to the improper handling of proxy requests by the affected software. An attacker could exploit this vulnerability to establish a TCP connection to a back-end server by sending a request that submits malicious input to a targeted Kubernetes API server. The attacker could then send arbitrary requests authenticated with the Transport Layer Security (TLS) credentials of the Kubernetes API server. A successful exploit could allow the attacker to gain elevated privileges on the system, which could be used to conduct further attacks.
Kubernetes has confirmed the vulnerability and released software updates.
To exploit this vulnerability, the attacker must send a request that submits malicious input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected systems.
Kubernetes has released a bug report at the following link: Bug #71411
Red Hat has released updated software for registered subscribers at the following link: Red Hat Network. Red Hat packages can be updated on Red Hat Enterprise Linux versions 5 and later using the yum tool.
Added new vendor and affected products information.
Vendor Announcements, Fixed Software, and Affected Products
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM
THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products
Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.