CVE-2019-18905 in Linux Enterprise Server
Summary
by MITRE
A Insufficient Verification of Data Authenticity vulnerability in autoyast2 of SUSE Linux Enterprise Server 12, SUSE Linux Enterprise Server 15 allows remote attackers to MITM connections when deprecated and unused functionality of autoyast is used to create images. This issue affects: SUSE Linux Enterprise Server 12 autoyast2 version 4.1.9-3.9.1 and prior versions. SUSE Linux Enterprise Server 15 autoyast2 version 4.0.70-3.20.1 and prior versions.
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Analysis
by VulDB Data Team • 05/13/2024
The vulnerability described in CVE-2019-18905 represents a critical insufficient verification of data authenticity flaw within the autoyast2 component of SUSE Linux Enterprise Server versions 12 and 15. This weakness specifically manifests when deprecated and unused functionality of autoyast is employed to generate system images, creating a pathway for remote attackers to execute man-in-the-middle attacks against affected systems. The vulnerability stems from inadequate validation mechanisms that fail to properly authenticate data integrity during the image creation process, leaving systems exposed to malicious interference. The affected versions include autoyast2 4.1.9-3.9.1 and prior for SUSE Linux Enterprise Server 12, along with autoyast2 4.0.70-3.20.1 and prior for SUSE Linux Enterprise Server 15, indicating a widespread impact across multiple server generations.
The technical exploitation of this vulnerability occurs through the manipulation of data flows during autoyast image creation processes, where attackers can intercept and modify network communications without proper authentication verification. This flaw operates at the protocol level where data authenticity checks are insufficiently implemented, allowing attackers to inject malicious content into the system image generation workflow. The deprecated autoyast functionality that remains enabled creates an attack surface that was never properly secured or removed from production environments. According to CWE classification, this vulnerability maps to CWE-295 which specifically addresses "Improper Certificate Validation" and "Insufficient Verification of Data Authenticity," highlighting the core weakness in cryptographic validation and data integrity checks.
The operational impact of this vulnerability extends beyond simple network interception as it fundamentally compromises the integrity of system image deployments across enterprise environments. When attackers successfully exploit this weakness, they can inject malicious code or configurations into system images, potentially leading to persistent backdoors, unauthorized access, or complete system compromise. The implications are particularly severe in enterprise contexts where automated deployment processes rely heavily on autoyast for consistent system provisioning, as a single compromised image can affect multiple systems during deployment. This vulnerability directly aligns with ATT&CK technique T1547.001 which covers "Registry Run Keys / Startup Folder" and T1059.001 which addresses "Command and Scripting Interpreter" through potential malicious code injection during system image creation.
Organizations should immediately implement mitigations including disabling the deprecated autoyast functionality when not actively required, implementing proper certificate validation mechanisms, and establishing network monitoring to detect anomalous traffic patterns during image creation processes. The most effective approach involves upgrading to patched versions of autoyast2 where available, or removing the deprecated functionality entirely from production environments. Network segmentation and traffic inspection should be employed to monitor for unauthorized modifications to deployment processes, while cryptographic validation should be strengthened to ensure data integrity during image creation workflows. Additionally, regular security assessments should verify that deprecated system components are properly decommissioned to prevent similar vulnerabilities from persisting in enterprise infrastructure.