CVE-2022-29178 in Cilium
Summary
by MITRE • 05/20/2022
Cilium is open source software for providing and securing network connectivity and loadbalancing between application workloads. Cilium prior to versions 1.9.16, 1.10.11, and 1.11.15 contains an incorrect default permissions vulnerability. Operating Systems with users belonging to the group ID 1000 can access the API of Cilium via Unix domain socket available on the host where Cilium is running. This could allow malicious users to compromise integrity as well as system availability on that host. The problem has been fixed and the patch is available in versions 1.9.16, 1.10.11, and 1.11.5. A potential workaround is to modify Cilium's DaemonSet to run with a certain command, which can be found in the GitHub Security Advisory for this vulnerability.
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Analysis
by VulDB Data Team • 05/27/2022
The vulnerability identified as CVE-2022-29178 affects Cilium, a popular open source software solution for network connectivity and load balancing in containerized environments. This issue represents a critical misconfiguration problem that stems from improper default permissions settings within the Cilium daemon implementation. The vulnerability specifically impacts versions prior to 1.9.16, 1.10.11, and 1.11.15, creating a significant security risk for organizations relying on Cilium for their network infrastructure. The flaw manifests through Unix domain socket exposure on host systems where Cilium operates, creating an attack surface that can be exploited by unauthorized users.
The technical flaw occurs when operating systems have users belonging to group ID 1000 that can access the Cilium API through Unix domain sockets available on the host system. This misconfiguration allows unauthorized access to the Cilium control plane through a default socket that lacks proper access controls. The vulnerability falls under CWE-732, which describes Incorrect Permission Assignment for Critical Resources, and represents a classic case of insufficient privilege separation. Attackers with access to group ID 1000 can exploit this weakness to compromise the integrity and availability of the host system, potentially leading to complete system compromise or denial of service conditions.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it creates a persistent threat vector that can be leveraged for various malicious activities. Compromised integrity means that attackers could modify network policies, routing rules, or other critical network configuration elements that Cilium manages. System availability is also at risk since attackers could potentially disrupt network connectivity or cause resource exhaustion through API abuse. The vulnerability affects organizations using containerized environments where Cilium serves as the primary network policy enforcement mechanism, making it particularly dangerous in cloud-native deployments and microservices architectures where network security is paramount.
Security professionals should immediately upgrade to the patched versions 1.9.16, 1.10.11, and 1.11.15 to remediate this vulnerability. The fix addresses the root cause by implementing proper socket permissions and access controls that prevent unauthorized users from accessing the Cilium API. Organizations can also implement workarounds as outlined in the GitHub Security Advisory, which involves modifying the Cilium DaemonSet configuration to run with specific command parameters that restrict socket access. This vulnerability aligns with ATT&CK technique T1068, which describes 'Exploitation for Privilege Escalation', and represents a common attack pattern where initial access through misconfigured services leads to broader system compromise. The remediation process should include thorough audit of existing Cilium deployments, verification of proper permissions on Unix domain sockets, and implementation of network segmentation controls to limit potential impact if similar vulnerabilities are discovered in other components.