CVE-2020-14869 in MySQL Server
Summary
by MITRE • 10/21/2020
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Security: LDAP Auth). Supported versions that are affected are 5.7.31 and prior and 8.0.21 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 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/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 • 11/24/2020
The vulnerability identified as CVE-2020-14869 resides within the MySQL Server authentication mechanism, specifically within the LDAP authentication component that forms part of Oracle MySQL's security infrastructure. This flaw affects multiple versions of both MySQL 5.7 and MySQL 8.0, with the affected versions being 5.7.31 and earlier, as well as 8.0.21 and earlier releases. The vulnerability represents a significant concern for database administrators and security professionals who rely on MySQL as their primary database management system, particularly in enterprise environments where authentication security and system availability are paramount. The issue manifests in the way MySQL Server handles LDAP authentication requests, creating a potential pathway for malicious actors to disrupt database operations.
The technical nature of this vulnerability stems from improper handling of certain LDAP authentication parameters that can lead to a denial of service condition. When an attacker with high privileges and network access attempts to establish an LDAP authentication session, the MySQL Server process can become unstable and either hang indefinitely or crash repeatedly. This behavior occurs because the server fails to properly validate or process specific input parameters during the LDAP authentication handshake process, leading to resource exhaustion or memory corruption that ultimately results in system instability. The vulnerability's exploitability is classified as easily accessible, meaning that sophisticated attack techniques are not required to trigger the flaw, making it particularly dangerous in environments where attackers may have elevated access levels.
From an operational impact perspective, this vulnerability presents a substantial risk to database availability and business continuity. The successful exploitation of CVE-2020-14869 can result in complete denial of service conditions where the MySQL Server becomes unavailable to legitimate users and applications. This type of disruption can cascade through entire enterprise systems that depend on database connectivity for their operations, potentially causing widespread service outages and financial losses. The CVSS 3.1 scoring system assigns this vulnerability a base score of 4.9, with the availability impact component rated as high, indicating that the primary concern is system unavailability rather than data compromise or confidentiality breaches. Organizations running affected MySQL versions face the risk of their database services becoming completely inaccessible, requiring manual intervention and system restarts to restore normal operations.
The vulnerability aligns with CWE-20, which describes "Improper Input Validation," and represents a specific instance where insufficient validation of authentication parameters leads to system instability. From an attacker's perspective, this flaw maps to several techniques within the ATT&CK framework, particularly those related to privilege escalation and denial of service operations. The fact that this vulnerability requires only high privileged access makes it particularly concerning as it suggests that insiders or attackers who have already gained elevated privileges could leverage this weakness to cause significant disruption. Organizations should implement immediate mitigations including applying the relevant Oracle patches, disabling LDAP authentication if not strictly required, and implementing network segmentation to limit access to database servers. Additionally, monitoring for unusual authentication patterns and implementing intrusion detection systems can help identify potential exploitation attempts before they cause complete service disruption. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the need for comprehensive security assessments of authentication mechanisms within database systems.