CVE-2020-2763 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Replication). Supported versions that are affected are 5.6.47 and prior, 5.7.29 and prior and 8.0.19 and prior. Easily exploitable 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 4.9 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 05/25/2024
The vulnerability identified as CVE-2020-2763 represents a significant availability risk within Oracle MySQL Server's replication functionality. This flaw exists in the Server: Replication component and affects multiple version lines including 5.6.47 and earlier, 5.7.29 and earlier, and 8.0.19 and earlier releases. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness through multiple protocols to compromise the affected MySQL servers. The security implications extend beyond simple data access as this vulnerability specifically targets the server's availability through a complete denial of service condition.
The technical nature of this vulnerability stems from issues within the replication mechanism that can cause the MySQL server to hang or experience frequently repeatable crashes when processing certain replication events. This type of flaw typically occurs when the server fails to properly validate or handle specific data patterns during replication operations, leading to resource exhaustion or internal state corruption. The vulnerability's CVSS score of 4.9 indicates a moderate to high severity impact on availability, with the vector AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H demonstrating that network-based attacks requiring high privileges can trigger complete system crashes. This vulnerability specifically affects the server's ability to maintain continuous operation, making it particularly dangerous in production environments where database availability is critical.
The operational impact of CVE-2020-2763 extends beyond simple service disruption as it can render MySQL servers completely unavailable to legitimate users and applications. When exploited, this vulnerability can cause repeated crashes that require manual intervention to restore service, potentially leading to extended downtime and data access interruptions. Organizations running affected MySQL versions face significant operational risks including potential data loss, service degradation, and business continuity impacts. The high privilege requirement suggests that this vulnerability is more likely to be exploited by insiders or attackers who have already compromised administrative credentials, making it particularly concerning for environments where privilege escalation is a concern.
From a cybersecurity perspective, this vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflow conditions and memory management issues that can lead to system instability. The attack surface is expanded by the multiple protocol support that enables exploitation, potentially through MySQL's native replication protocols, network-based attacks, or even through compromised administrative interfaces. Organizations should consider implementing network segmentation and access controls to limit exposure, while also monitoring for unusual replication activity that might indicate exploitation attempts. The vulnerability's classification under the ATT&CK framework would likely map to T1489 (Service Stop) and T1070 (Indicator Removal) techniques, as attackers could potentially use this vulnerability to disrupt services and then remove evidence of their activities.
Mitigation strategies should focus on immediate patch deployment for all affected MySQL versions, with comprehensive testing to ensure compatibility with existing applications. Organizations should also implement monitoring solutions that can detect replication anomalies and system instability patterns that might indicate exploitation attempts. Network-level controls including firewall rules and access control lists can help limit the attack surface by restricting access to MySQL replication ports and services. Regular security assessments should include vulnerability scanning for replication components, and incident response plans should account for potential service disruption scenarios. The remediation process should also involve reviewing and strengthening administrative access controls to minimize the risk of privilege escalation attacks that could exploit this vulnerability.