CVE-2018-2769 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Pluggable Auth). 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-2018-2769 resides within Oracle MySQL's Server component, specifically affecting the Pluggable Authentication subsystem. This weakness impacts MySQL versions 5.7.21 and earlier, representing a significant security concern for database administrators and system operators. The vulnerability operates at a foundational level within the authentication framework, making it particularly dangerous as it can be exploited by attackers with elevated privileges who possess network access to the target system. The affected subsystem handles authentication mechanisms that are critical to database security, creating a potential attack surface that could lead to complete service disruption.
The technical flaw manifests as a vulnerability that allows authenticated attackers with high privileges to exploit network protocols and cause a denial of service condition. This weakness specifically affects the server's ability to handle authentication requests properly, leading to potential hangs or repeated crashes that can completely disable the MySQL service. The vulnerability's exploitability is classified as easily accessible due to the combination of requiring only high privilege levels and network access through multiple protocols. The authentication subsystem's design flaw creates a scenario where malicious input or requests can trigger memory corruption or resource exhaustion, ultimately resulting in system instability and service unavailability.
From an operational perspective, this vulnerability presents a substantial risk to database availability and system reliability. Successful exploitation can result in complete denial of service conditions that may require manual intervention to restore normal operations, potentially causing extended downtime for applications dependent on MySQL services. The impact severity, rated at CVSS 3.0 base score of 4.9 with availability impacts, indicates that while the vulnerability does not provide direct data access or modification capabilities, it can effectively disable critical database services. Organizations relying on MySQL for business-critical applications face potential operational disruptions that could affect multiple dependent systems and services. The vulnerability's characteristics align with CWE-121, which describes heap-based buffer overflow conditions, and may also relate to CWE-122, concerning stack-based buffer overflow issues in authentication handling.
The attack surface for this vulnerability spans multiple network protocols, making it particularly concerning for environments where MySQL services are exposed to various connection methods. This characteristic means that attackers could potentially exploit the vulnerability through different communication channels, increasing the likelihood of successful compromise. The CVSS vector analysis reveals that the vulnerability requires high privilege levels to exploit, suggesting that it may be more accessible to insiders or attackers who have already gained some level of access to the system. However, the network accessibility aspect means that even with limited initial access, attackers can leverage this weakness to escalate their impact. Organizations should consider this vulnerability in the context of ATT&CK framework's privilege escalation and denial of service tactics, as it provides a mechanism for maintaining persistent access while simultaneously disrupting services.
Mitigation strategies should focus on immediate patching of affected MySQL versions to 5.7.22 or later, which contains the necessary security fixes. System administrators should also implement network segmentation and access controls to limit exposure of MySQL services to only authorized networks and users. Additional protective measures include monitoring for unusual authentication patterns and implementing intrusion detection systems that can identify potential exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in authentication subsystems. Organizations should also maintain comprehensive backup and recovery procedures to ensure rapid restoration of services in case of successful exploitation. The vulnerability highlights the importance of keeping database software up to date and implementing defense-in-depth strategies that protect authentication mechanisms from both external and internal threats.