CVE-2021-45708 in abomonation Crate
Summary
by MITRE • 12/27/2021
An issue was discovered in the abomonation crate through 2021-10-17 for Rust. Because transmute operations are insufficiently constrained, there can be an information leak or ASLR bypass.
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Analysis
by VulDB Data Team • 12/30/2021
The vulnerability identified as CVE-2021-45708 resides within the abomonation crate, a Rust library designed for efficient serialization and deserialization of data structures. This crate operates by leveraging unsafe Rust operations to achieve high performance serialization, particularly through the use of transmute functions that convert between different data types at runtime. The issue emerged from insufficient constraints placed on these transmute operations, which are fundamental to the crate's ability to handle complex data structures efficiently. When developers use abomonation for serialization, the library internally employs transmute calls to convert between different memory representations, creating a potential attack surface that could be exploited by malicious actors.
The technical flaw manifests when the transmute operations within abomonation fail to properly validate memory layouts and type safety constraints. This occurs because the crate does not adequately verify that the source and destination types are compatible in terms of memory layout, alignment, and size requirements. When such validation is missing, an attacker can potentially manipulate serialized data in ways that cause the transmute operations to access memory regions that should remain protected or hidden. The vulnerability enables information leakage through memory access patterns that bypass normal type checking mechanisms, allowing attackers to read data that should be inaccessible through regular program execution paths. Additionally, the insufficient constraints can lead to Address Space Layout Randomization bypasses, where attackers can predict or determine memory layout information that should remain randomized for security purposes.
The operational impact of CVE-2021-45708 extends beyond simple information disclosure, as it can be leveraged to undermine fundamental security protections in applications that rely on abomonation for data serialization. Systems using this crate become vulnerable to attacks that could extract sensitive information from memory, potentially including cryptographic keys, user credentials, or other confidential data. The ASLR bypass capability significantly weakens the security posture of affected applications by removing a crucial defense mechanism that randomizes memory layout to prevent exploitation of memory corruption vulnerabilities. This vulnerability affects any Rust application or library that utilizes the abomonation crate for serialization operations, making it particularly concerning for systems handling sensitive data where memory safety is paramount.
Mitigation strategies for CVE-2021-45708 require immediate attention from developers and system administrators. The primary recommendation involves upgrading to a patched version of the abomonation crate where the transmute operations have been properly constrained and validated. Security teams should conduct comprehensive audits of their codebases to identify all instances where abomonation is used for serialization, particularly in applications handling sensitive data. Additionally, implementing runtime checks and memory validation routines can help detect and prevent exploitation attempts. Organizations should also consider implementing additional security controls such as stack canaries, memory protection mechanisms, and regular security scanning of dependencies to prevent similar vulnerabilities from being introduced through third-party libraries. The vulnerability aligns with CWE-476 which addresses NULL Pointer Dereference, and potentially CWE-121 which covers Stack-based Buffer Overflow, though the specific nature of this vulnerability is more aligned with improper handling of memory layout and type safety in unsafe code operations. From an ATT&CK perspective, this vulnerability maps to techniques involving privilege escalation and information gathering through memory access patterns, potentially enabling more sophisticated attacks when combined with other exploitation vectors.