Remote code execution via allocator size wraparound
Published May 3, 2022 · Updated Apr 16, 2025
Integer overflow in tos_mmheap_alloc in Tencent TencentOS Tiny 3.1.0 allows remote attackers to crash devices or execute code. The allocator calculates the effective allocation size with wrapping integer arithmetic, producing an incorrect memory assignment for attacker-controlled input. Network reachability without authentication or user interaction is sufficient; exploitation can interrupt the device or run code in its RTOS context.
Summary
What happened
Integer overflow in tos_mmheap_alloc in Tencent TencentOS Tiny 3.1.0 allows remote attackers to crash devices or execute code. The allocator calculates the effective allocation size with wrapping integer arithmetic, producing an incorrect memory assignment for attacker-controlled input. Network reachability without authentication or user interaction is sufficient; exploitation can interrupt the device or run code in its RTOS context.
The record
- CVE
- CVE-2021-27439
- Published
- May 3, 2022
- Updated
- Apr 16, 2025
- Vendor
- Tencent
- Product
- TencentOS Tiny
- Classifications
- CWE-190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 3, 2022CVE publishedPublication date reported by the CVE source.
- Apr 16, 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?
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- Affected versionversion=3.1.0
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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