CVE-2023-31039 in bRPC
Summary
by MITRE • 05/08/2023
Security vulnerability in Apache bRPC <1.5.0 on all platforms allows attackers to execute arbitrary code via ServerOptions::pid_file. An attacker that can influence the ServerOptions pid_file parameter with which the bRPC server is started can execute arbitrary code with the permissions of the bRPC process.
Solution: 1. upgrade to bRPC >= 1.5.0, download link: https://dist.apache.org/repos/dist/release/brpc/1.5.0/ https://dist.apache.org/repos/dist/release/brpc/1.5.0/ 2. If you are using an old version of bRPC and hard to upgrade, you can apply this patch: https://github.com/apache/brpc/pull/2218 https://github.com/apache/brpc/pull/2218
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Analysis
by VulDB Data Team • 10/16/2024
The CVE-2023-31039 vulnerability represents a critical remote code execution flaw in Apache bRPC versions prior to 1.5.0, where attackers can manipulate the ServerOptions::pid_file parameter to achieve arbitrary code execution with the privileges of the running bRPC process. This vulnerability falls under the CWE-15 category of Improper Neutralization of Data in a Command, specifically manifesting as command injection through improper handling of file path parameters. The flaw exists in the server initialization process where the pid_file parameter is not properly sanitized before being used in system calls or file operations, creating a pathway for malicious input to be interpreted as executable commands rather than simple file paths.
The technical exploitation of this vulnerability occurs when an attacker can control the ServerOptions::pid_file value during bRPC server startup, allowing them to craft malicious input that gets processed without adequate validation or sanitization. This creates a scenario where the bRPC process, running with elevated privileges, executes unintended commands through the compromised pid_file parameter. The vulnerability is particularly dangerous because it operates at the system call level, meaning that successful exploitation results in code execution with the same permissions as the bRPC service itself, potentially leading to full system compromise if the service runs with administrative privileges.
The operational impact of CVE-2023-31039 extends beyond simple code execution to encompass complete system compromise when the bRPC service operates with elevated privileges. Attackers can leverage this vulnerability to establish persistent backdoors, escalate privileges, or perform reconnaissance activities within the target environment. The vulnerability is classified under the MITRE ATT&CK framework as a command injection technique, specifically mapping to T1059.001 - Command and Scripting Interpreter: PowerShell, where the malicious input gets executed through system-level commands. Organizations using affected bRPC versions face significant risk, particularly in environments where bRPC services are exposed to untrusted networks or where the service runs with high-privilege accounts.
Mitigation strategies for CVE-2023-31039 center on immediate version upgrades to bRPC 1.5.0 or later, which incorporates proper input validation and sanitization for the pid_file parameter. The patch referenced in the official fix addresses the root cause by implementing proper parameter validation and ensuring that user-controlled input cannot be interpreted as system commands. Organizations unable to perform immediate upgrades should apply the specific patch available from the Apache bRPC repository, which implements the necessary safeguards to prevent malicious input from being processed as executable commands. Additionally, network segmentation and access controls should be implemented to limit exposure of bRPC services to untrusted networks, while monitoring systems should be configured to detect anomalous file creation patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and the principle of least privilege in preventing command injection attacks.