CVE-2018-25026 in actix-web Crate
Summary
by MITRE • 12/27/2021
An issue was discovered in the actix-web crate before 0.7.15 for Rust. It can add the Send marker trait to an object that cannot be sent between threads safely, leading to memory corruption.
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Analysis
by VulDB Data Team • 12/30/2021
The vulnerability identified as CVE-2018-25026 represents a critical memory safety issue within the actix-web crate version 0.7.14 and earlier, affecting Rust-based web applications that utilize this framework. This flaw resides in the crate's handling of type safety and thread safety guarantees, specifically concerning the Send marker trait which is fundamental to Rust's concurrency model. The issue manifests when the crate incorrectly applies the Send marker trait to objects that are not actually safe to transfer between threads, creating a dangerous condition that can lead to undefined behavior and memory corruption.
The technical root cause of this vulnerability stems from improper type system handling within the actix-web framework's internal implementation. When the crate processes certain types and applies the Send trait automatically, it fails to properly validate whether these types actually satisfy the requirements for thread-safe transmission. This flaw is particularly insidious because it operates at the type system level, making it difficult to detect during normal code review processes. The vulnerability is classified under CWE-472 as an External Control Flow Interference, though it more accurately represents a type safety violation that allows for memory corruption through improper trait application.
From an operational perspective, this vulnerability poses significant risks to web applications built using actix-web, as it can lead to crashes, data corruption, and potentially arbitrary code execution when malicious inputs trigger the flawed code path. Attackers could exploit this weakness by crafting requests that cause the framework to incorrectly apply thread safety markers to non-thread-safe objects, potentially leading to heap corruption or other memory safety violations. The impact extends beyond simple application crashes, as the memory corruption could be leveraged for more sophisticated attacks, particularly in environments where the web application has elevated privileges or handles sensitive data.
The security implications of CVE-2018-25026 align with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as the vulnerability could enable attackers to manipulate memory contents through improper trait handling, potentially leading to code injection scenarios. The flaw also intersects with ATT&CK technique T1555.003 for Credentials from Password Stores, as memory corruption could expose sensitive information stored in affected applications. Organizations using actix-web versions prior to 0.7.15 should prioritize immediate remediation through version upgrades, as the vulnerability exists in the core type handling mechanisms of the framework. The recommended mitigation strategy involves upgrading to actix-web version 0.7.15 or later, which implements proper validation of Send trait application and ensures that only truly thread-safe objects receive the Send marker trait. Additionally, developers should conduct thorough code audits to identify any custom implementations that might inadvertently trigger similar type safety issues within their applications.