CVE-2023-43768 in Server
Summary
by MITRE • 03/27/2024
An issue was discovered in Couchbase Server 6.6.x through 7.2.0, before 7.1.5 and 7.2.1. Unauthenticated users may cause memcached to run out of memory via large commands.
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Analysis
by VulDB Data Team • 08/06/2024
The vulnerability identified as CVE-2023-43768 represents a significant memory exhaustion flaw within Couchbase Server versions spanning 6.6.x through 7.2.0, affecting systems prior to the patched releases of 7.1.5 and 7.2.1. This issue specifically targets the memcached component that operates as part of the Couchbase Server architecture, creating a pathway for unauthenticated attackers to exploit memory resource depletion through the submission of oversized command payloads. The vulnerability stems from insufficient input validation mechanisms within the memcached protocol implementation, allowing malicious actors to craft commands that consume excessive memory resources without proper authentication or authorization checks. This weakness directly impacts the server's ability to maintain stable operations and can lead to service disruption or complete system unavailability.
The technical exploitation of this vulnerability occurs through the memcached protocol interface where unauthenticated users can submit commands containing oversized data payloads that exceed normal operational limits. When the memcached component processes these malformed commands, it allocates memory resources proportional to the command size without adequate bounds checking or resource limiting mechanisms. The flaw operates at the protocol level where memcached handles client requests, making it particularly dangerous as it bypasses traditional authentication mechanisms and can be exploited from any network location without requiring valid credentials. This vulnerability is categorized under CWE-400 as "Uncontrolled Resource Consumption" and aligns with ATT&CK technique T1499.004 for "Network Denial of Service" through resource exhaustion attacks that target memory allocation mechanisms.
The operational impact of CVE-2023-43768 extends beyond simple service disruption to potentially compromise the entire Couchbase deployment infrastructure. When exploited successfully, the memory exhaustion attack can cause the memcached process to consume all available memory resources, leading to system instability, process crashes, and subsequent denial of service for legitimate users. The vulnerability affects database availability and can result in data access interruptions that impact business operations, particularly in environments where Couchbase serves as a critical data store for applications and services. Organizations running affected Couchbase versions face increased risk of operational downtime and potential data access limitations that can cascade into broader system failures. The vulnerability also creates opportunities for attackers to perform reconnaissance activities by observing system behavior under memory stress conditions, potentially revealing additional system information that could aid in further exploitation attempts.
Mitigation strategies for CVE-2023-43768 primarily involve applying the vendor-provided patches and updates that address the memory handling inconsistencies within the memcached protocol implementation. Organizations should immediately upgrade to Couchbase Server versions 7.1.5 or 7.2.1, which contain the necessary fixes to prevent oversized command processing and implement proper resource limits. Network-level mitigations should include implementing firewall rules to restrict access to memcached ports to trusted networks only, as well as deploying intrusion detection systems that can monitor for unusual command sizes or patterns. Additionally, administrators should configure memory limits and resource constraints within the Couchbase configuration files to prevent individual processes from consuming excessive system resources. The implementation of monitoring solutions that track memory usage patterns and alert on anomalous resource consumption can provide early detection capabilities for potential exploitation attempts. Security teams should also conduct regular vulnerability assessments to identify any unpatched systems and implement network segmentation to limit the potential impact of successful exploitation attempts.