CVE-2018-2779 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 5.7.21 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 • 03/02/2023
The vulnerability identified as CVE-2018-2779 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent of Oracle MySQL. This flaw affects versions 5.7.21 and earlier, representing a significant security concern for database administrators and system operators who rely on MySQL for critical data operations. The vulnerability operates at a fundamental level within the database query optimization engine, which is responsible for determining the most efficient execution path for SQL queries. The affected optimizer functionality processes complex query structures and execution plans, making it a critical component for database performance and stability.
The technical nature of this vulnerability stems from improper handling of certain query execution scenarios within the optimizer module. When specific complex queries are processed through the affected MySQL versions, the optimizer fails to properly manage memory allocation and execution flow, leading to unpredictable behavior that can result in system instability. This flaw manifests as a condition where the database server becomes unresponsive or experiences repeated crashes, effectively rendering the database service unavailable to legitimate users and applications. The vulnerability's exploitability is considered high due to the fact that it can be triggered through network-based attacks, requiring minimal privileges beyond basic network access. The attack vector operates across multiple protocols, including TCP/IP connections to the MySQL service port, making it particularly dangerous in environments where database services are accessible over networks.
The operational impact of CVE-2018-2779 represents a severe availability threat to MySQL deployments, with the potential to cause complete denial of service conditions. When successfully exploited, the vulnerability can force the MySQL server to enter a state of indefinite hanging or frequent crashes, effectively terminating database operations and disrupting business continuity. This type of vulnerability directly violates the availability principles of the CIA triad, as it compromises the ability of authorized users to access database resources. The CVSS 3.0 score of 4.9 reflects the moderate to high severity impact, with the availability impact rated as high at 8.0, indicating that the vulnerability can cause significant disruption to database services. Organizations running affected MySQL versions face the risk of extended downtime, data access interruptions, and potential financial losses due to service unavailability.
Security professionals should immediately implement mitigations to protect against exploitation of this vulnerability. The primary and most effective mitigation strategy involves applying the official Oracle security patches and updates that address the specific optimizer flaw. Database administrators should also consider implementing network-level restrictions such as firewall rules that limit access to MySQL service ports to trusted networks only, reducing the attack surface. Monitoring systems should be configured to detect unusual patterns of database service disruptions or connection terminations that might indicate exploitation attempts. Additionally, organizations should review and implement proper access controls to ensure that only authorized privileged users have network access to MySQL services, as the vulnerability requires high-privilege network access to exploit. This vulnerability aligns with CWE-119, which addresses "Improper Access to Resources via Universal Resource Identifier" and relates to ATT&CK technique T1499.004 for "Endpoint Denial of Service" within the context of database service disruption. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in database configurations and ensure comprehensive protection against similar threats.