Overview
A critical vulnerability, identified as CVE-2025-5866, has been discovered in RT-Thread 5.1.0 that poses a significant risk to system integrity and data privacy. This vulnerability specifically affects the sys_sigprocmask function within the file rt-thread/components/lwp/lwp_syscall.c. By exploiting this vulnerability, an attacker could manipulate the ‘how’ argument, leading to an improper validation of array index. This vulnerability is of particular concern due to the potential for system compromise and data leakage.
Vulnerability Summary
CVE ID: CVE-2025-5866
Severity: Critical (CVSS: 8.0)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
Product | Affected Versions
RT-Thread | 5.1.0
How the Exploit Works
The exploit takes advantage of the sys_sigprocmask function of the RT-Thread 5.1.0. By manipulating the ‘how’ argument, an attacker can cause an improper validation of the array index. This can lead to unexpected behavior, potentially allowing a malicious user to execute arbitrary code, compromise the system, or leak sensitive data.
Conceptual Example Code
While no specific exploit code has been made public, a conceptual example might involve passing an unexpected value to the ‘how’ argument in the sys_sigprocmask function. This could potentially be done via a crafted system call or manipulated user input. The following pseudocode might represent an example of how this could occur:
#include "rtthread.h"
void exploit() {
// Obtain a handle to the vulnerable function
void (*vulnerable_function)(int, const rt_sigset_t *, rt_sigset_t *) = &rt_sys_sigprocmask;
// Create a signal set
rt_sigset_t sigset;
// Set all bits in the signal set
sigset = -1;
// Call the vulnerable function with an unexpected 'how' argument
vulnerable_function(9999, &sigset, NULL);
}This is a simplified example and actual exploitation may involve more complex steps and knowledge of the internals of RT-Thread.
Mitigation
Users are advised to apply the vendor patch as soon as it becomes available. In the meantime, the use of a web application firewall (WAF) or intrusion detection system (IDS) may provide temporary mitigation. However, these should not be considered long-term solutions, as they may not completely prevent exploitation of this vulnerability.
