CVE-2017-3633 in Communications
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Memcached). Supported versions that are affected are 5.6.36 and earlier and 5.7.18 and earlier. Difficult to exploit vulnerability allows unauthenticated attacker with network access via Memcached 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 6.5 (Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H).
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Analysis
by VulDB Data Team • 04/09/2023
The vulnerability identified as CVE-2017-3633 resides within the MySQL Server component, specifically in the Server: Memcached subcomponent, representing a critical security weakness that affects multiple versions of Oracle MySQL. This flaw manifests in the way MySQL handles connections through its Memcached interface, creating a pathway for malicious actors to exploit the system without requiring authentication credentials. The vulnerability impacts MySQL Server versions 5.6.36 and earlier, as well as 5.7.18 and earlier, making it a widespread concern across numerous production environments that have not been updated to newer releases. The nature of this vulnerability allows for unauthenticated network-based attacks, meaning that any individual with access to the network can potentially exploit the flaw without needing to present valid credentials or establish legitimate connections to the database system.
The technical implementation of this vulnerability stems from improper handling of Memcached protocol connections within the MySQL server environment, creating a scenario where network traffic can be manipulated to cause system instability and unauthorized data manipulation. This flaw operates at the protocol level, where the server fails to properly validate incoming connections or requests through the Memcached interface, allowing attackers to send malformed or malicious requests that can trigger unexpected behavior within the MySQL server process. The vulnerability's classification as difficult to exploit indicates that while the attack vector requires some network access and understanding of the Memcached protocol, the actual exploitation process does not require complex attack chains or privilege escalation. The CVSS score of 6.5 reflects the balanced impact across integrity and availability concerns, with the availability impact being particularly severe as attackers can cause complete denial of service through system hangs or crashes.
The operational impact of this vulnerability extends beyond simple system availability issues to encompass data integrity concerns that can compromise the reliability of database operations. Successful exploitation of CVE-2017-3633 can result in complete system denial of service, where the MySQL server becomes unresponsive or crashes repeatedly, effectively rendering database services unavailable to legitimate users and applications. Additionally, the vulnerability enables unauthorized modification of database content, allowing attackers to perform unauthorized updates, inserts, or deletes on specific portions of the database that the system has access to. This dual impact on availability and integrity creates a particularly dangerous scenario where database systems can be both rendered unusable and have their data corrupted or altered without proper authorization. The vulnerability's potential to cause frequent crashes and system hangs can lead to extended downtime and data recovery complications, while the data modification capabilities pose significant risks to business continuity and regulatory compliance.
Organizations affected by this vulnerability should prioritize immediate remediation through patching or upgrading to MySQL versions that have addressed this specific flaw, as the vulnerability's network accessibility means that systems exposed to the internet or internal networks are at risk of exploitation. The implementation of network segmentation and firewall rules to restrict access to Memcached ports can serve as a temporary mitigation strategy while longer-term solutions are deployed, though this approach only reduces risk rather than eliminating it entirely. Security monitoring should be enhanced to detect unusual patterns in database connection attempts or protocol violations that might indicate exploitation attempts, with particular attention to Memcached protocol interactions. According to CWE standards, this vulnerability aligns with CWE-20, which addresses improper input validation, and CWE-119, which deals with insufficient protection of data within memory, both of which are fundamental security principles that should be maintained in database server implementations. The ATT&CK framework categorizes this vulnerability under the T1071.004 technique for application layer protocol usage, specifically targeting the Memcached protocol as an attack vector to compromise database systems. Organizations should also consider implementing database activity monitoring solutions that can detect unauthorized data modifications and system disruptions that may result from exploitation of this vulnerability, ensuring that security operations teams have visibility into potential attacks against their MySQL infrastructure.