CVE-2020-2806 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Compiling). Supported versions that are affected are 5.7.28 and prior. Difficult to exploit vulnerability allows low 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 5.3 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H).
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/25/2024
The vulnerability identified as CVE-2020-2806 represents a critical availability risk within Oracle MySQL Server versions 5.7.28 and earlier, specifically affecting the Server: Compiling component. This flaw manifests as a buffer overflow condition that occurs during the compilation process of SQL statements, creating a pathway for malicious actors to disrupt database operations. The vulnerability's classification as difficult to exploit indicates that while the attack vector requires some technical skill, the potential impact on system availability makes it a significant concern for database administrators and security teams. The CVSS 3.0 score of 5.3 reflects the moderate severity of the availability impact, with the attack requiring network access and low privilege levels, yet capable of causing complete denial of service through system hangs or repeated crashes.
The technical implementation of this vulnerability stems from improper bounds checking during SQL statement compilation within the MySQL server's processing pipeline. When maliciously crafted SQL queries are processed through the server's compilation engine, the insufficient validation allows for memory corruption that can trigger unpredictable behavior in the database service. This buffer overflow condition specifically targets the server's ability to handle complex SQL constructs and can be exploited through multiple network protocols including TCP/IP connections, making the attack surface broader than typical single-protocol vulnerabilities. The vulnerability's design aligns with CWE-121, which describes stack-based buffer overflow conditions, and demonstrates how improper memory management in database query processing can create severe availability risks.
From an operational perspective, successful exploitation of CVE-2020-2806 can result in complete service disruption for MySQL database instances, forcing administrators to restart services and potentially causing data loss or transaction failures. The vulnerability's ability to cause repeated crashes means that even a single successful attack can maintain system instability until manual intervention occurs. Organizations relying on MySQL for critical business operations face significant risk of operational downtime, particularly in environments where database availability is paramount for business continuity. The low privilege requirement and network-based attack vector make this vulnerability particularly dangerous as it can be exploited by attackers with minimal access rights, potentially leading to cascading failures in database-dependent applications and services.
Mitigation strategies for CVE-2020-2806 should prioritize immediate patching of affected MySQL Server installations to version 5.7.29 or later, where Oracle has implemented fixes for the buffer overflow condition. Network segmentation and firewall rules should be implemented to limit access to MySQL ports, particularly restricting connections to only trusted IP addresses and applications. Monitoring systems should be enhanced to detect unusual patterns of database connection failures or service restarts that could indicate exploitation attempts. Database administrators should implement connection pooling and redundancy measures to minimize the impact of potential service disruptions. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar memory corruption vulnerabilities in other database components, with particular attention to the ATT&CK framework's T1499 technique for resource hijacking through availability attacks. Organizations should also maintain comprehensive incident response plans that include specific procedures for handling MySQL service disruptions and database recovery operations.