CVE-2019-15544 in protobuf Crate
Summary
by MITRE
An issue was discovered in the protobuf crate before 2.6.0 for Rust. Attackers can exhaust all memory via Vec::reserve calls.
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Analysis
by VulDB Data Team • 12/04/2023
The vulnerability identified as CVE-2019-15544 affects the protobuf crate version 2.5.0 and earlier in the Rust programming language ecosystem. This issue represents a critical memory exhaustion flaw that can be exploited by attackers to consume all available system memory through carefully crafted input data. The vulnerability specifically targets the internal memory allocation mechanisms within the protobuf serialization and deserialization processes, where the crate fails to properly validate or limit memory consumption during vector reservation operations.
The technical root cause of this vulnerability lies in the improper handling of memory allocation within the protobuf crate's implementation. When processing serialized data, the crate performs Vec::reserve calls without adequate bounds checking or memory consumption limits. This allows attackers to craft malicious protobuf messages that trigger excessive memory allocation requests, causing the application to allocate progressively larger amounts of memory until system resources are exhausted. The flaw operates at the memory management level where the reserve function is called without proper validation of the requested capacity, leading to unbounded memory growth patterns. This vulnerability aligns with CWE-772, which addresses Missing Release of Memory after Effective Lifetime, and represents a classic example of a memory exhaustion attack vector.
The operational impact of CVE-2019-15544 extends beyond simple resource exhaustion, as it can lead to complete system instability and denial of service conditions. Applications using vulnerable versions of the protobuf crate become susceptible to memory exhaustion attacks that can crash services, cause system hangs, or enable attackers to consume all available memory resources. This vulnerability particularly affects systems where protobuf serialization is used for processing untrusted input data, such as network services, API endpoints, or any application that deserializes protobuf messages from external sources. The attack surface is broad given the widespread use of protobuf in Rust applications and microservices architectures, making this vulnerability particularly dangerous in production environments where resource constraints are critical.
Mitigation strategies for CVE-2019-15544 focus on immediate version upgrades to protobuf crate version 2.6.0 or later, which contains the necessary fixes for memory allocation bounds checking. System administrators and developers should prioritize updating their dependencies to ensure the patched version is deployed across all affected applications. Additionally, implementing input validation and size limits for protobuf message processing can provide defensive measures against exploitation attempts. Organizations should also consider implementing monitoring and alerting systems to detect unusual memory consumption patterns that might indicate exploitation attempts. The fix addresses the underlying memory management issue by introducing proper bounds checking for Vec::reserve operations and implementing reasonable limits on memory allocation during protobuf processing. This vulnerability demonstrates the importance of proper resource management in serialization libraries and highlights the need for robust input validation in all data processing components, aligning with ATT&CK technique T1499.001 for Network Denial of Service attacks through resource exhaustion.