CVE-2020-36212 in abi_stable Crate
Summary
by MITRE • 01/26/2021
An issue was discovered in the abi_stable crate before 0.9.1 for Rust. DrainFilter lacks soundness because of a double drop.
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Analysis
by VulDB Data Team • 02/20/2021
The vulnerability identified as CVE-2020-36212 affects the abi_stable crate version 0.9.0 and earlier in the Rust programming language ecosystem. This issue manifests within the DrainFilter functionality which is part of the crate's memory management utilities. The flaw represents a critical soundness issue that can lead to undefined behavior in applications utilizing this crate. The vulnerability specifically stems from improper handling of memory resources during the drain filtering operation, creating conditions where memory objects may be dropped twice, leading to potential system instability and security risks.
The technical root cause of this vulnerability lies in the implementation of the DrainFilter trait within the abi_stable crate. When processing collections through the drain filter operation, the crate fails to properly manage the lifecycle of memory resources, resulting in a double drop scenario. This occurs because the internal implementation does not correctly track ownership semantics or properly handle the transition of memory ownership during the filtering process. The double drop vulnerability is particularly dangerous because it can lead to memory corruption, heap corruption, or other forms of undefined behavior that may be exploited by malicious actors. This issue falls under the CWE-415 vulnerability category, which specifically addresses double free errors in memory management.
From an operational perspective, this vulnerability poses significant risks to applications that rely on the abi_stable crate for maintaining ABI stability across different Rust versions or for creating safe FFI boundaries. The impact extends beyond simple memory corruption as it can potentially enable attackers to execute arbitrary code or cause denial of service conditions. Applications using the affected crate may experience crashes, data corruption, or other stability issues when processing collections through drain filter operations. The vulnerability is particularly concerning in systems where memory safety is paramount, such as systems programming, embedded applications, or any environment where Rust's memory safety guarantees are critical to overall system integrity. The issue can be exploited through normal usage patterns of the crate, making it particularly dangerous as it does not require special conditions or privileges to trigger.
Mitigation strategies for this vulnerability primarily involve upgrading to version 0.9.1 or later of the abi_stable crate where the double drop issue has been resolved. System administrators and developers should conduct immediate inventory checks to identify all applications and dependencies that utilize the affected crate version. The fix implemented in version 0.9.1 addresses the ownership tracking mechanisms and ensures proper memory lifecycle management during drain filter operations. Organizations should also consider implementing automated dependency scanning tools to identify and remediate similar vulnerabilities across their software supply chain. Additionally, developers should review their code for potential reliance on the affected functionality and ensure that proper memory management practices are followed even when using third-party crates. The remediation process should include thorough regression testing to verify that the upgrade does not introduce compatibility issues or break existing functionality. This vulnerability highlights the importance of proper memory management in systems programming and demonstrates how seemingly minor implementation flaws can have significant security implications in Rust applications.