CVE-2019-10192 in Hyperloglog Data Structure
Summary
by MITRE
A heap-buffer overflow vulnerability was found in the Redis hyperloglog data structure versions 3.x before 3.2.13, 4.x before 4.0.14 and 5.x before 5.0.4. By carefully corrupting a hyperloglog using the SETRANGE command, an attacker could trick Redis interpretation of dense HLL encoding to write up to 3 bytes beyond the end of a heap-allocated buffer.
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Analysis
by VulDB Data Team • 10/24/2023
The heap-buffer overflow vulnerability CVE-2019-10192 represents a critical security flaw in Redis database systems affecting multiple major versions including 3.x before 3.2.13, 4.x before 4.0.14, and 5.x before 5.0.4. This vulnerability specifically targets the hyperloglog data structure implementation within Redis, which is used for cardinality estimation and probabilistic data structures. The flaw stems from improper bounds checking during the processing of hyperloglog data when manipulated through the SETRANGE command, creating a condition where memory corruption can occur beyond allocated buffer boundaries.
The technical exploitation of this vulnerability involves crafting malicious hyperloglog data structures that deliberately corrupt the dense encoding format used by Redis for efficient storage. When Redis processes these corrupted structures through the SETRANGE command, the system fails to properly validate buffer boundaries during memory operations, allowing an attacker to write up to three bytes beyond the allocated heap buffer. This type of buffer overflow creates a potential for arbitrary code execution or system instability, as the overflow can overwrite adjacent memory regions including function pointers, return addresses, or other critical data structures within the Redis process memory space.
The operational impact of CVE-2019-10192 extends beyond simple memory corruption, as it provides attackers with a pathway for privilege escalation and system compromise within environments where Redis is deployed. The vulnerability affects Redis installations that utilize hyperloglog functionality, which is commonly used in applications requiring efficient cardinality estimation such as web analytics, network monitoring, and user tracking systems. Attackers can leverage this flaw to execute remote code on vulnerable Redis servers, potentially gaining unauthorized access to sensitive data or using the compromised system as a pivot point for further attacks within network infrastructure. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and CWE-121 for stack-based buffer overflow, though the specific implementation manifests as heap-based memory corruption.
Mitigation strategies for CVE-2019-10192 primarily focus on immediate patching of affected Redis versions to their respective secure releases including 3.2.13, 4.0.14, and 5.0.4. Organizations should implement network segmentation to limit access to Redis instances and employ strict input validation for all commands processed through the SETRANGE functionality. Additional defensive measures include monitoring for anomalous hyperloglog data structures, implementing intrusion detection systems to identify potential exploitation attempts, and conducting regular security assessments of Redis deployments. The vulnerability demonstrates the importance of proper memory management in database systems and highlights the need for comprehensive input validation across all data structure processing operations, particularly in probabilistic data structures that require complex memory layout management.