CVE-2021-28033 in byte_struct Crate
Summary
by MITRE • 03/05/2021
An issue was discovered in the byte_struct crate before 0.6.1 for Rust. There can be a drop of uninitialized memory if a certain deserialization method panics.
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Analysis
by VulDB Data Team • 03/07/2021
The vulnerability identified as CVE-2021-28033 represents a critical memory safety issue within the byte_struct crate version 0.6.0 and earlier, affecting Rust applications that utilize this library for binary data processing. This flaw manifests during deserialization operations when specific error conditions trigger unexpected behavior in the memory management system. The issue stems from improper handling of uninitialized memory structures that can lead to undefined behavior when panic conditions occur during the deserialization process.
The technical root cause of this vulnerability lies in the crate's implementation of memory cleanup routines during error scenarios. When a deserialization method encounters a panic condition, the crate's drop implementation attempts to clean up memory resources that may not have been properly initialized. This creates a scenario where destructors operate on uninitialized memory regions, potentially leading to memory corruption, information disclosure, or arbitrary code execution depending on the specific context and memory layout. The flaw specifically affects the byte_struct crate's handling of binary data structures and their associated memory management during error recovery paths.
From an operational perspective, this vulnerability poses significant risks to systems that rely on binary data serialization and deserialization processes, particularly in network services, file processing applications, and any software that handles untrusted binary input. Attackers could potentially exploit this weakness by crafting malicious binary data that triggers the panic condition during deserialization, leading to memory corruption that might be leveraged for privilege escalation or denial of service attacks. The vulnerability is particularly concerning in environments where the affected crate is used in security-sensitive applications or systems handling sensitive data.
The impact of this vulnerability aligns with CWE-457, which describes "Use of Uninitialized Variable" and CWE-755, "Improper Handling of Exceptional Conditions," both of which are directly applicable to the memory management failure and panic handling issues present in the byte_struct crate. This vulnerability also maps to ATT&CK technique T1059.007 for "Command and Scripting Interpreter: Python" in scenarios where attackers might leverage memory corruption to execute arbitrary code, though the specific implementation requires careful exploitation. Organizations should prioritize updating to version 0.6.1 or later of the byte_struct crate to address this memory safety issue, implementing comprehensive testing to ensure that no other components are vulnerable to similar uninitialized memory access patterns.
Mitigation strategies should include immediate patching of the affected crate version, implementation of comprehensive input validation for binary data processing, and deployment of memory safety monitoring tools to detect potential exploitation attempts. Security teams should also conduct thorough code reviews focusing on memory management patterns in all binary data handling libraries, particularly examining how destructors and cleanup routines interact with error conditions. Additionally, application developers should consider implementing defensive programming practices such as zero-initializing memory regions before use and employing memory safety tools like valgrind or address sanitizers during development and testing phases to identify similar issues in other components of their software stack.