Overview
The focus of this article is on a critical vulnerability that has been identified in Rancher, a popular open-source software for managing Kubernetes in production. This vulnerability, identified as CVE-2024-22036, can be exploited to escape the chroot jail and gain root access to the Rancher container itself. This poses a significant security risk as it allows potential attackers to escalate their privileges and potentially compromise the system. Given the widespread use of Rancher in production environments, the security implications of this vulnerability are far-reaching and warrant immediate attention.
Vulnerability Summary
CVE ID: CVE-2024-22036
Severity: Critical (CVSS Score 9.1)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
No phone number, email, or personal info required.
Product | Affected Versions
Rancher | 2.7.0 to 2.7.15
Rancher | 2.8.0 to 2.8.8
Rancher | 2.9.0 to 2.9.2
How the Exploit Works
The vulnerability arises due to a flaw in the way Rancher manages cluster or node drivers. These drivers can be manipulated by a potential attacker to escape the chroot jail, thus obtaining root access to the Rancher container. This can result in the attacker gaining unrestricted access to the system and potentially compromising it. In production environments, further privilege escalation is possible based on living off the land within the Rancher container itself.
Conceptual Example Code
Below is a
conceptual
example of how this vulnerability might be exploited. Keep in mind that this example is not meant to be a working exploit, but a simplified demonstration of the exploit concept.
# An attacker might use a command like this to manipulate the driver
$ echo "exploit code here" > /path/to/driver
# Then, they might attempt to escape the chroot jail
$ chroot --userspec=root:root /
# If successful, they would now have root access to the Rancher container
$ id
uid=0(root) gid=0(root) groups=0(root)Mitigation and Remediation
Users of affected versions of Rancher are advised to update to the latest patched versions immediately to mitigate this vulnerability. The issue is fixed in Rancher versions 2.7.16, 2.8.9 and 2.9.3. As a temporary mitigation, users can also employ a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) to detect and prevent exploit attempts. However, these are just temporary solutions and updating to the patched versions is strongly advised to fully secure your systems.