CVE-2020-2898 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Charsets). The supported version that is affected is 8.0.19. 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-2020-2898 resides within the MySQL Server component responsible for character set handling, specifically affecting version 8.0.19 of Oracle MySQL. This issue represents a significant availability risk that can be exploited by attackers with high privileges and network access through multiple protocols. The vulnerability falls under the Common Weakness Enumeration category CWE-121, which deals with stack-based buffer overflow conditions, though the specific manifestation in this case involves memory corruption during character set processing operations. The attack vector requires network connectivity and elevated privileges, indicating that the vulnerability is not trivially exploitable by casual attackers but poses a genuine threat to systems where administrative access has been compromised or where privilege escalation has occurred.
The technical flaw manifests when the MySQL server processes certain character set operations that trigger memory corruption within the charset handling subsystem. This corruption can lead to unpredictable behavior including system hangs or repeated crashes that effectively render the database service unavailable. The vulnerability's impact on system availability is rated at CVSS 3.0 score of 4.9, which represents a moderate to high severity threat in terms of availability impact. The complete denial of service condition means that legitimate users would be unable to access database services until the server is manually restarted or the underlying memory corruption is resolved through system restart or patching. The vulnerability's exploitability is classified as easily achievable due to the combination of high privileges required and the multiple protocol access vectors available, including TCP/IP connections and other network-based interfaces that MySQL typically supports.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect business continuity and data availability for organizations relying on MySQL 8.0.19. When a MySQL server becomes unresponsive or crashes repeatedly, it can cause cascading failures in applications that depend on database connectivity, leading to extended downtime and potential data loss scenarios. The vulnerability's characteristics align with ATT&CK technique T1499.004, which covers "Trusted Relationship" and "Network Denial of Service" tactics, as the compromised server can no longer provide its intended service to authorized users. Organizations utilizing this specific MySQL version should consider immediate patching to address the vulnerability, as the availability impact can severely disrupt business operations. The vulnerability also represents a potential indicator of compromise in security monitoring systems, as repeated crashes or hangs may be flagged as anomalous behavior in normal database operations, providing an additional detection mechanism for security teams to identify when such attacks may be occurring.
Mitigation strategies should include immediate deployment of Oracle's official patches for MySQL 8.0.19, which address the character set processing flaw through memory management improvements and bounds checking. Organizations should also implement network segmentation and access controls to limit the attack surface, ensuring that only authorized administrative users can establish connections to database servers. Monitoring should be enhanced to detect unusual patterns of server crashes or hangs, particularly those occurring during character set operations or when specific database queries are executed. Security teams should also consider implementing intrusion detection systems that can identify network-based attacks targeting MySQL services and maintain regular backups to ensure quick recovery from potential service disruptions. The vulnerability serves as a reminder of the importance of keeping database management systems updated and the critical need for proper privilege management to prevent high-privileged attackers from exploiting availability-related flaws in database servers.