9.8

CVE-2021-27435: arm mbed Integer Overflow or Wraparound

CVSS: 9.8v3.1CriticalModified
Published 03-05-2022Last modified 16-04-2025

Vulnerability summary

CVE-2021-27435 is a critical (CVSS 9.8) Integer Overflow or Wraparound vulnerability in arm mbed. EPSS estimates a 1.86% chance of exploitation in the next 30 days, higher than 78.9% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
1.86%
0%100%
Low · +0.12 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Timeline

  1. 03-05-2022
    PublishedVulnerability first disclosed.
  2. 16-04-2025
    Last modifiedVulnerability information updated.

Description

ARM mbed product Version 6.3.0 is vulnerable to integer wrap-around in malloc_wrapper function, which can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.86%

Chance of exploitation in the next 30 days

Percentile

79%

Versus all other CVEs

30-day change

+0.12 pp

From 1.74% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.86%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Mbed Os

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Arm1 product

1 vendor · 1 product

References

2 links