CVE-2017-3309 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 5.5.54 and earlier, 5.6.35 and earlier and 5.7.17 and earlier. Easily "exploitable" vulnerability allows low privileged attacker with network access via multiple protocols to compromise MySQL Server. While the vulnerability is in MySQL Server, attacks may significantly impact additional products. 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 7.7 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 12/20/2020
The vulnerability identified as CVE-2017-3309 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent of Oracle MySQL database systems. This flaw affects multiple version ranges including 5.5.54 and earlier, 5.6.35 and earlier, and 5.7.17 and earlier, representing a significant portion of the MySQL ecosystem that was in active use during the time of discovery. The vulnerability's classification as easily exploitable indicates that attackers with minimal privileges and network access can leverage this weakness, making it particularly concerning for database security. The attack vector requires network access via multiple protocols, suggesting that the vulnerability could be exploited across various communication channels that MySQL supports.
The technical nature of this vulnerability stems from improper handling within the query optimizer module of MySQL Server, which is responsible for determining the most efficient execution plan for database queries. When processing certain malformed or crafted queries, the optimizer fails to properly validate input parameters, leading to a condition where memory corruption or resource exhaustion can occur. This flaw specifically 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 and applications. The vulnerability's impact extends beyond just the MySQL Server itself, as successful exploitation can potentially affect dependent systems and applications that rely on database connectivity for their operations.
The operational impact of CVE-2017-3309 represents a critical availability threat that can severely disrupt business operations and data services. Organizations relying on MySQL databases for critical applications face the risk of complete service outages when this vulnerability is exploited, potentially resulting in significant financial losses, data unavailability, and damage to customer confidence. The CVSS 3.0 Base Score of 7.7 indicates a high severity level with availability impacts being the primary concern, while the vector (AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H) demonstrates that the attack requires low complexity, low privilege level, and can cause cascading effects across multiple systems. The vulnerability's potential to cause frequent crashes or hangs makes it particularly dangerous as it can lead to sustained service disruption rather than a one-time incident.
Organizations should immediately implement mitigation strategies including applying the relevant security patches provided by Oracle to address this vulnerability, as well as implementing network segmentation and access controls to limit exposure. The recommended approach involves upgrading to patched versions of MySQL Server, specifically versions beyond the affected ranges mentioned in the vulnerability description. Additionally, monitoring systems should be enhanced to detect unusual patterns of database connection failures or service disruptions that might indicate exploitation attempts. From a security framework perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Network administrators should also consider implementing intrusion detection systems that can identify suspicious query patterns and unauthorized access attempts to database servers. The vulnerability highlights the critical importance of maintaining up-to-date database security patches and implementing comprehensive monitoring strategies to protect against such availability-focused attacks that can severely impact business continuity.