CVE-2019-2991 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.017 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 as well as unauthorized update, insert or delete access to some of MySQL Server accessible data. CVSS 3.0 Base Score 5.5 (Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H).
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Analysis
by VulDB Data Team • 01/15/2024
The vulnerability identified as CVE-2019-2991 resides within the MySQL Server optimizer component of Oracle MySQL, affecting versions 8.0.17 and earlier. This flaw represents a critical security weakness that operates at the intersection of database integrity and availability, with implications spanning across multiple network protocols. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness to compromise the target MySQL server infrastructure. The attack vector specifically requires network connectivity and utilizes multiple protocols, suggesting the vulnerability may manifest across various communication channels that MySQL typically supports.
The technical nature of this vulnerability lies within the server optimizer module, which is responsible for processing and executing database queries efficiently. When exploited, this flaw enables attackers to trigger either a complete denial of service condition through server hangs or frequent crashes, effectively rendering the database unavailable to legitimate users. Additionally, the vulnerability grants unauthorized capabilities to modify database content through update, insert, or delete operations against certain portions of the server's accessible data. This dual impact on availability and integrity creates a particularly dangerous scenario for database environments where both continuous operation and data consistency are paramount. The CVSS 3.0 score of 5.5 reflects the moderate severity of this vulnerability, considering its potential to cause significant disruption while requiring elevated privileges for exploitation.
From an operational standpoint, this vulnerability presents substantial risks to database administrators and security teams responsible for maintaining MySQL server environments. The ability to cause repeated crashes or hangs can severely impact business operations, particularly in mission-critical applications where database availability is essential for system functionality. Organizations running affected MySQL versions face potential data corruption scenarios, as unauthorized modification capabilities could lead to inconsistent database states or loss of critical information. The requirement for high-privileged network access suggests that this vulnerability is more likely to be exploited by insiders or attackers who have already gained elevated access to the network infrastructure, making it particularly concerning for environments where privilege escalation has occurred.
Security mitigations for CVE-2019-2991 should prioritize immediate patching of affected MySQL server installations to version 8.0.18 or later, which contains the necessary fixes for this optimizer-related vulnerability. Network segmentation and access controls should be reinforced to limit the attack surface, particularly restricting network access to MySQL servers and implementing strict authentication mechanisms. Monitoring systems should be enhanced to detect unusual patterns of server crashes or repeated connection failures that might indicate exploitation attempts. The vulnerability aligns with CWE-119 which addresses improper restriction of operations within a limited scope, and potentially relates to ATT&CK technique T1070.004 for indicator removal and T1489 for denial of service through multiple protocols. Organizations should also conduct comprehensive vulnerability assessments to identify other potential optimizer-related weaknesses and ensure proper network access controls are in place to minimize the risk of exploitation.