CVE-2018-11218 in Redis
Summary
by MITRE
Memory Corruption was discovered in the cmsgpack library in the Lua subsystem in Redis before 3.2.12, 4.x before 4.0.10, and 5.x before 5.0 RC2 because of stack-based buffer overflows.
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Analysis
by VulDB Data Team • 03/27/2023
The vulnerability CVE-2018-11218 represents a critical memory corruption issue within the cmsgpack library implementation in Redis software across multiple versions. This flaw exists within the Lua subsystem of Redis, specifically affecting versions prior to 3.2.12, 4.0.10, and 5.0 RC2. The vulnerability stems from improper handling of stack-based buffer overflows during message packing operations, creating a pathway for adversaries to exploit memory corruption conditions that could lead to arbitrary code execution or system compromise.
The technical implementation of this vulnerability involves stack-based buffer overflows that occur when the cmsgpack library processes incoming data structures within Redis's Lua environment. When Redis receives malformed or specially crafted data through Lua scripting capabilities, the cmsgpack library fails to properly validate buffer boundaries, allowing attackers to overwrite adjacent memory locations on the stack. This type of vulnerability is categorized under CWE-121 Stack-based Buffer Overflow, which directly enables attackers to manipulate program execution flow through memory corruption techniques. The flaw specifically manifests when Redis processes complex data structures that are serialized using the cmsgpack format, commonly used in Lua script execution contexts.
The operational impact of CVE-2018-11218 extends beyond simple memory corruption, presenting significant security risks to Redis deployments. Attackers can leverage this vulnerability to execute arbitrary code on affected systems, potentially leading to complete system compromise, data exfiltration, or service disruption. The vulnerability is particularly dangerous in environments where Redis is used as a backend service for applications requiring high availability and security, as it could allow attackers to gain unauthorized access to sensitive data stored in Redis databases. Additionally, the vulnerability's presence in multiple Redis version lines means that organizations running any of the affected versions face potential exposure, regardless of their specific deployment environment or use case.
Mitigation strategies for CVE-2018-11218 require immediate version updates to Redis 3.2.12, 4.0.10, or 5.0 RC2, which contain patches addressing the stack-based buffer overflow conditions. Organizations should also implement network segmentation and access controls to limit exposure of Redis instances to untrusted networks, while monitoring for suspicious network traffic patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Lua scripting and T1068 for local privilege escalation, making defensive measures crucial for protecting Redis deployments. System administrators should also consider implementing intrusion detection systems that can identify anomalous Lua script execution patterns and establish regular security audits of Redis configurations to prevent exploitation of this and similar memory corruption vulnerabilities.