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.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
1.86%
0%100%
Low · +0.12 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 03-05-2022PublishedVulnerability first disclosed.
- 16-04-2025Last 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 versionsCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSources2 sources · 7.3–9.8
- CVE.orgCNA7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LDiffers
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
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 score1.86%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundMbed Os
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Arm1 product
- mbed6.3.0
1 vendor · 1 product
References
2 links- www.cisa.gov/uscert/ics/advisories/icsa-21-119-04X Refsource CONFIRMThird Party AdvisoryUS Government Resource
- github.com/ARMmbed/mbed-os/pull/14408X Refsource CONFIRMExploitIssue TrackingPatchThird Party Advisory