Kernel crash via unchecked syscall array index
Published Jun 9, 2025 · Updated Jun 9, 2025
Memory corruption in RT-Thread 5.1.0 allows local users to crash the kernel by passing an invalid how value to sys_sigprocmask. In lwp_syscall.c, sys_sigprocmask uses the user-controlled how value directly as the mask_command_u2k array index without checking its bounds. A compromised user thread can reach the syscall; public evidence establishes a kernel-crash path and out-of-bounds memory access, but not reliable privilege escalation.
Summary
What happened
Memory corruption in RT-Thread 5.1.0 allows local users to crash the kernel by passing an invalid how value to sys_sigprocmask. In lwp_syscall.c, sys_sigprocmask uses the user-controlled how value directly as the mask_command_u2k array index without checking its bounds. A compromised user thread can reach the syscall; public evidence establishes a kernel-crash path and out-of-bounds memory access, but not reliable privilege escalation.
The record
- CVE
- CVE-2025-5866
- Published
- Jun 9, 2025
- Updated
- Jun 9, 2025
- Vendor
- RT-Thread
- Product
- RT-Thread
- Classifications
- CWE-129, CWE-119, T1499
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 9, 2025CVE publishedPublication date reported by the CVE source.
- Jun 9, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.1.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- sys_sigprocmask out-of-bounds index reportproof of concept · unverified
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Technologies
Your stack
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Your stack
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