CVE-2020-36207 in aovec Crate
Summary
by MITRE • 01/26/2021
An issue was discovered in the aovec crate through 2020-12-10 for Rust. Because Aovec does not have bounds on its Send trait or Sync trait, a data race and memory corruption can occur.
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Analysis
by VulDB Data Team • 02/20/2021
The vulnerability identified as CVE-2020-36207 resides within the aovec crate for Rust programming language, a library designed to provide atomic vector operations. This crate was vulnerable due to improper implementation of the Send and Sync traits, which are fundamental to Rust's memory safety guarantees and concurrent programming model. The absence of proper bounds on these traits creates a critical weakness that undermines the language's safety mechanisms.
The technical flaw manifests when the aovec crate fails to properly constrain the Send and Sync traits, allowing types that should not be safely shared between threads to be considered as such. According to CWE-362, this represents a concurrent execution using improper synchronization, specifically a race condition vulnerability. When code attempts to use atomic vector operations in concurrent contexts, the lack of trait bounds means the compiler cannot verify that the operations are safe across thread boundaries, leading to potential data races where multiple threads access shared data simultaneously without proper synchronization.
The operational impact of this vulnerability is severe as it can result in memory corruption and undefined behavior within applications using the affected crate. When data races occur due to improper Send and Sync trait implementations, memory corruption can manifest in various forms including heap corruption, use-after-free conditions, or other memory safety violations that can be exploited for arbitrary code execution. This vulnerability directly affects Rust applications that rely on concurrent programming patterns, particularly those utilizing atomic operations across multiple threads.
Mitigation strategies for CVE-2020-36207 involve updating to a newer version of the aovec crate where the Send and Sync traits have been properly constrained with appropriate bounds. System administrators and developers should also implement comprehensive code review processes to identify other crates that may suffer from similar trait implementation issues. The vulnerability aligns with ATT&CK technique T1059.008, which involves execution through script-based languages, as it can lead to code execution through memory corruption exploits. Additionally, organizations should consider implementing dependency scanning tools that can detect such unsafe trait implementations in their software supply chains. The fix typically requires ensuring that types implementing Send and Sync traits have proper bounds that prevent unsafe concurrent access patterns, aligning with Rust's safety guarantees and preventing the conditions that lead to data races and memory corruption.