CVE-2019-15522 in csync2
Summary
by MITRE
An issue was discovered in LINBIT csync2 through 2.0. csync_daemon_session in daemon.c neglects to force a failure of a hello command when the configuration requires use of SSL.
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Analysis
by VulDB Data Team • 04/18/2024
The vulnerability identified as CVE-2019-15522 resides within the LINBIT csync2 software version 2.0 and earlier, representing a critical security flaw in the daemon component responsible for maintaining synchronization between cluster nodes. This issue manifests in the csync_daemon_session function located in the daemon.c source file, where the system fails to enforce mandatory SSL usage even when the configuration explicitly requires it. The flaw creates a potential security risk by allowing unencrypted communication channels to be established despite security policies that mandate encrypted connections, undermining the integrity of the cluster's communication infrastructure.
This technical vulnerability directly relates to CWE-319, which addresses the exposure of sensitive information through improper use of encryption, and CWE-326, concerning the inadequate protection of sensitive information by weak encryption mechanisms. The root cause stems from insufficient validation of SSL requirements within the session establishment process, allowing attackers to bypass security controls that should enforce encrypted communication. When the configuration specifies that SSL must be used for all connections, the csync_daemon_session function fails to implement this requirement, creating a path for potential man-in-the-middle attacks and unauthorized data interception.
The operational impact of this vulnerability extends beyond simple communication security, as it compromises the fundamental trust model of the csync2 cluster environment. Attackers could exploit this weakness to intercept synchronization data between cluster nodes, potentially gaining access to sensitive configuration information, file contents, or system states that should remain protected. The vulnerability affects systems where csync2 is used for cluster synchronization, particularly in environments where data integrity and confidentiality are paramount, such as high availability clusters, storage systems, and distributed computing environments. This flaw essentially renders the SSL configuration settings ineffective, creating a false sense of security for administrators who believe their systems are properly secured.
Mitigation strategies for CVE-2019-15522 should focus on immediate patching of the csync2 software to version 2.0 or later, where the issue has been resolved. System administrators should also implement network-level monitoring to detect unauthorized unencrypted communication attempts and verify that SSL requirements are properly enforced through configuration audits. The ATT&CK framework categorizes this vulnerability under T1046, Network Service Scanning, as attackers may attempt to identify systems that have not properly enforced SSL requirements, and T1566, Phishing, if the vulnerability is exploited through social engineering to gain access to systems with weak security configurations. Organizations should conduct comprehensive security assessments of their cluster environments to ensure that all communication channels are properly encrypted and that configuration management practices enforce mandatory SSL usage across all nodes.