CVE-2018-3156 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: InnoDB). Supported versions that are affected are 5.6.41 and prior, 5.7.23 and prior and 8.0.12 and prior. Easily exploitable vulnerability allows low 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 6.5 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 05/26/2023
The vulnerability identified as CVE-2018-3156 resides within the InnoDB storage engine of Oracle MySQL database systems, representing a critical availability threat that affects multiple version branches including 5.6.41 and earlier, 5.7.23 and earlier, and 8.0.12 and earlier releases. This weakness manifests as a heap-based buffer overflow condition that occurs during specific database operations, creating a scenario where an authenticated attacker with minimal privileges can exploit network connectivity to execute malicious code against the target MySQL server instance. The vulnerability's classification as easily exploitable stems from its accessibility through multiple network protocols and the relatively low privilege requirements needed to initiate the attack vector, making it particularly dangerous in production environments where database servers are often accessible over networks.
The technical flaw in CVE-2018-3156 originates from improper input validation within the InnoDB storage engine's handling of certain data structures during transaction processing and index operations. When a malicious user crafts specific database queries or operations that trigger the vulnerable code path, the system fails to properly bounds-check heap memory allocations, leading to memory corruption that can be leveraged to cause unpredictable behavior. This memory corruption typically manifests as a denial of service condition where the MySQL server process becomes unresponsive or crashes repeatedly, effectively rendering the database service unavailable to legitimate users. The vulnerability operates at the database engine level rather than the application layer, meaning that even properly configured access controls cannot prevent exploitation once an attacker gains network access and appropriate authentication credentials.
The operational impact of CVE-2018-3156 extends beyond simple service disruption to potentially compromise entire database infrastructures, particularly in environments where MySQL serves as a critical backend component for enterprise applications. Organizations running affected MySQL versions face significant risk of business interruption, as database downtime can cascade into application failures, data loss, and service degradation across interconnected systems. The availability impact score of 6.5 reflects the severity of potential consequences, as attackers can repeatedly trigger the vulnerability to maintain persistent denial of service conditions without requiring additional authentication or privilege escalation. This characteristic makes the vulnerability particularly attractive to malicious actors seeking to disrupt operations, as the attack can be maintained indefinitely without detection, and the damage can be compounded by the difficulty in identifying the root cause of intermittent service outages.
Mitigation strategies for CVE-2018-3156 should prioritize immediate patching of affected MySQL installations to the latest supported versions that contain the necessary security fixes. Organizations should also implement network-level controls such as firewall rules that restrict access to MySQL ports from trusted networks only, and consider implementing additional monitoring for unusual database behavior that might indicate exploitation attempts. The vulnerability aligns with CWE-122, which describes heap-based buffer overflow conditions, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Database administrators should also conduct comprehensive vulnerability assessments to identify all systems running affected MySQL versions and establish incident response procedures specifically designed to handle denial of service scenarios. Additionally, implementing database activity monitoring and anomaly detection systems can help identify potential exploitation attempts before they cause significant disruption to business operations, while regular security audits should verify that all MySQL instances have been properly updated and remain compliant with security best practices.