Amazon Web Services (AWS) FreeRTOS through 1.3.1 allows remote attackers to execute arbitrary code because of mbedTLS context object corruption in prvSetupConnection and GGD_SecureConnect_Connect in AWS TLS connectivity modules.
Conclusion & alert: CVE-2018-16528 is rated Moderate Risk (63.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.29%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 2.82% | 3.29% | +0.47% |
| 2 | 2025-11-06 | 2.93% | 2.82% | -0.11% |
| 3 | 2025-09-21 | — | 2.93% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.1 | 3.0 | HIGH |
|
2.2 | 5.9 | [email protected] |
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| amazon | amazon_web_services_freertos | <= 1.3.1 | cpe:2.3:a:amazon:amazon_web_services_freertos:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://blog.zimperium.com/freertos-tcpip-stack-vulnerabilities-details/ | Third Party Advisory |
| https://blog.zimperium.com/freertos-tcpip-stack-vulnerabilities-put-wide-range-devices-risk-compromise-smart-homes-critical-infrastructure-systems/ | Third Party Advisory |
| https://github.com/aws/amazon-freertos/blob/v1.3.2/CHANGELOG.md | Third Party Advisory |