CVE-2017-3640 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: DML). Supported versions that are affected are 5.7.18 and earlier. 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 • 01/04/2021
The vulnerability identified as CVE-2017-3640 resides within Oracle MySQL Server's DML (Data Manipulation Language) subsystem, specifically affecting versions 5.7.18 and earlier. This represents a significant security weakness that operates at the core of database operations, where DML commands such as INSERT, UPDATE, and DELETE are processed. The vulnerability's classification as easily exploitable indicates that attackers with relatively high privileges and network access can leverage this flaw to compromise the database server. The attack vector is particularly concerning as it operates across multiple network protocols, making the exploitation surface broader and more accessible to threat actors.
The technical nature of this vulnerability manifests as a flaw in how MySQL Server handles certain DML operations, leading to potential system instability. When exploited, the vulnerability enables attackers to cause either a complete hang or frequent crashes of the MySQL Server process, effectively creating a denial of service condition. This behavior aligns with CWE-119 which addresses improper access to memory locations, suggesting that the vulnerability likely involves buffer overflows or memory corruption during DML processing. The availability impact is severe as demonstrated by the CVSS 3.0 base score of 4.9, which reflects the system's inability to provide services to legitimate users due to the server crashes or hangs that occur as a result of exploitation.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire database infrastructure. Organizations relying on MySQL Server for critical business operations face significant risk when this vulnerability exists in their environment, as the resulting denial of service can impact multiple applications and services that depend on database availability. The high privilege requirement for exploitation suggests that this vulnerability may be targeted at attackers who have already gained some level of access to the system or network, potentially representing an escalation of privileges attack. The CVSS vector analysis reveals that while network access is required, the attack complexity is low, indicating that the exploitation process does not require advanced technical skills or specialized tools, making it particularly dangerous for organizations with less sophisticated security postures.
Mitigation strategies for CVE-2017-3640 should prioritize immediate patching of affected MySQL Server installations to version 5.7.19 or later, which contains the necessary security fixes. Organizations should implement network segmentation and access controls to limit the attack surface, ensuring that only authorized personnel can access database servers with elevated privileges. Monitoring systems should be enhanced to detect unusual patterns of database server behavior that might indicate exploitation attempts, including frequent crashes or connection timeouts. The vulnerability also highlights the importance of maintaining up-to-date security patches across all database systems, as this represents a clear example of how even minor version differences can introduce critical security gaps. Additionally, implementing intrusion detection systems and database activity monitoring tools can help identify potential exploitation attempts before they result in successful denial of service attacks, aligning with defensive strategies outlined in the ATT&CK framework under database attack patterns and privilege escalation techniques.