CVE-2017-3647 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Replication). Supported versions that are affected are 5.6.36 and earlier and 5.7.18 and earlier. Difficult to exploit vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.0 Base Score 4.4 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 01/04/2021
The vulnerability identified as CVE-2017-3647 resides within the MySQL Server replication functionality, specifically affecting Oracle MySQL versions 5.6.36 and earlier, as well as 5.7.18 and earlier. This issue represents a significant security concern within database infrastructure, as it targets the replication mechanism that enables data synchronization between primary and secondary database servers. The vulnerability's classification as a high-privileged attack vector indicates that exploitation requires existing administrative access or network-level privileges, making it particularly concerning for environments where database administrators maintain elevated permissions. The affected replication component is critical for maintaining data consistency across distributed database systems, which amplifies the potential impact of this flaw.
The technical nature of CVE-2017-3647 manifests as a flaw in how MySQL Server processes replication events, creating conditions that can lead to system instability and complete denial of service. Attackers with network access and high privileges can trigger a specific sequence of operations that causes the MySQL Server process to enter a state of permanent hang or frequent crashes, effectively rendering the database service unavailable to legitimate users. This vulnerability operates through multiple network protocols, increasing its attack surface and making it more challenging to defend against. The complexity of exploitation requires a sophisticated understanding of MySQL's internal replication mechanisms and network communication patterns, though the availability impact is severe enough to warrant immediate attention.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire database infrastructures, particularly in production environments where replication is essential for business continuity. Organizations relying on MySQL replication for disaster recovery, load balancing, or data distribution may face critical service interruptions that can cascade into broader business operations. The CVSS 3.0 score of 4.4 reflects the vulnerability's medium severity in terms of exploitability complexity, but the high availability impact rating indicates that successful exploitation can result in complete system unavailability. This characteristic places the vulnerability in the category of denial-of-service threats that can have significant business implications, especially when considering that database services often form the foundation of enterprise applications.
Security professionals should implement immediate mitigation strategies focusing on patch management and network segmentation to reduce exposure to this vulnerability. Organizations should prioritize upgrading to MySQL versions that address this specific replication flaw, as Oracle has released patches for affected versions. Network-level controls should be implemented to restrict access to MySQL replication ports and protocols, particularly for systems that do not require external replication connectivity. Monitoring solutions should be enhanced to detect unusual patterns of replication activity that might indicate exploitation attempts, while also implementing robust backup and recovery procedures to minimize downtime during potential incidents. This vulnerability demonstrates the importance of maintaining current database software versions and implementing comprehensive security monitoring for critical infrastructure components. The issue aligns with CWE-119, which addresses memory safety and improper access to memory locations, and represents a potential entry point for attackers seeking to establish persistent access or cause operational disruption in database environments. Organizations should also consider implementing the principle of least privilege for database replication accounts and regularly audit replication configurations to prevent unauthorized access to sensitive database operations.