What is CVE-2021-27439?

CVE-2021-27439 is a high-severity vulnerability in Tencent Tencentos-Tiny, classified under Integer Overflow or Wraparound. CVSS score: 7.3/10. Published 2022-05-03.

How severe is CVE-2021-27439?

High severity. CVSS v3 base score is 7.3 out of 10.

Integer overflow in Tencent Tencentos-Tiny

CVE-2021-27439

TencentOS-tiny version 3.1.0 is vulnerable to integer wrap-around in function 'tos_mmheap_alloc incorrect calculation of effective memory allocation size. This improper memory assignment can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

Vulnerability class: Integer Overflow

Published 2022-05-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.016 (74.2th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.016 · change: +0.001

Affected products

Tencent Tencentos-Tiny — versions 3.1.0
Tencentos-Tiny — versions 3.1.0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

www.cisa.gov/uscert/ics/advisories/icsa-21-119-04 (US Government Resource, Third Party Advisory)

Frequently asked questions

What is CVE-2021-27439?: CVE-2021-27439 is a high-severity vulnerability in Tencent Tencentos-Tiny, classified under Integer Overflow or Wraparound. CVSS score: 7.3/10. Published 2022-05-03.
How severe is CVE-2021-27439?: High severity. CVSS v3 base score is 7.3 out of 10.