CVE-2019-3685 in Open Build Service
Summary
by MITRE
Open Build Service before version 0.165.4 diddn't validate TLS certificates for HTTPS connections with the osc client binary
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Analysis
by VulDB Data Team • 02/04/2024
The Open Build Service represents a distributed build system that enables organizations to create and manage software packages across multiple platforms and architectures. This system operates through a client-server architecture where the osc client binary communicates with the build service server over HTTPS connections to retrieve package information, submit builds, and manage project configurations. The vulnerability described in CVE-2019-3685 specifically targets the client-side certificate validation mechanism within the osc binary, creating a significant security risk for users who rely on this build infrastructure for their software development workflows.
The technical flaw in CVE-2019-3685 stems from insufficient TLS certificate validation within the Open Build Service client implementation. When the osc client establishes HTTPS connections to communicate with the build service server, it fails to properly validate the server's TLS certificate against trusted certificate authorities. This omission allows an attacker positioned in the network path between the client and server to perform man-in-the-middle attacks by presenting a fraudulent certificate that the client will accept without proper verification. The vulnerability specifically affects versions prior to 0.165.4, indicating that the developers had not yet implemented adequate certificate validation routines in their codebase.
The operational impact of this vulnerability extends beyond simple data interception, as it fundamentally undermines the security assurances provided by HTTPS encryption. An attacker could exploit this weakness to modify package contents during transmission, inject malicious code into build processes, or redirect the client to compromised servers that appear legitimate. This risk is particularly severe in development environments where build systems are frequently accessed by multiple users and where the integrity of software packages is paramount. The vulnerability enables attackers to compromise the entire software supply chain, potentially affecting thousands of packages and projects that depend on the build service for their operations.
Organizations using Open Build Service versions prior to 0.165.4 should immediately implement mitigations to address this vulnerability. The primary remediation involves upgrading to version 0.165.4 or later, which includes proper TLS certificate validation mechanisms. Additionally, system administrators should verify that their client configurations enforce strict certificate validation and consider implementing additional network-level protections such as firewall rules that restrict access to known good build service endpoints. This vulnerability aligns with CWE-295 which addresses improper certificate validation and relates to ATT&CK technique T1071.004 for application layer protocol: DNS, though the specific attack vector here involves HTTPS protocol manipulation rather than DNS resolution.
The broader implications of this vulnerability highlight the critical importance of proper TLS implementation in client applications, particularly those handling sensitive build and deployment operations. Security practitioners should recognize that certificate validation is not merely a network security control but a fundamental requirement for maintaining the integrity of client-server communications in distributed systems. Organizations should establish regular audit procedures to verify that all client applications properly validate TLS certificates and maintain up-to-date security practices to prevent similar vulnerabilities from emerging in their software development infrastructure.