How severe is CVE-2018-16523?

CVE-2018-16523 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2018-16523 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16523?

CVE-2018-16523 primarily affects Amazon Amazon Web Services Freertos. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-16523?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-16523 published?

CVE-2018-16523 was published on 2018-12-06 and last updated on 2026-06-17.

CVE-2018-16523

CVE-2018-16523 is a high-severity vulnerability in Amazon Amazon Web Services Freertos with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-369.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v2: 5.8
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-369
Affected product: Amazon Amazon Web Services Freertos
Published: 2018-12-06
Last modified: 2026-06-17

Description

Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Connect middleware TCP/IP component allow division by zero in prvCheckOptions.

Frequently asked questions

What is CVE-2018-16523?: Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Connect middleware TCP/IP component allow division by zero in prvCheckOptions.
How severe is CVE-2018-16523?: CVE-2018-16523 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2018-16523 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16523?: CVE-2018-16523 primarily affects Amazon Amazon Web Services Freertos. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-16523?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-16523 published?: CVE-2018-16523 was published on 2018-12-06 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:amazon:amazon_web_services_freertos:*:*:*:*:*:*:*:*
cpe:2.3:a:amazon:freertos:*:*:*:*:*:*:*:*

More vulnerabilities in Amazon Amazon Web Services Freertos

CVE-2018-16601 — High (CVSS 8.1): An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with…
CVE-2018-16528 — High (CVSS 8.1): Amazon Web Services (AWS) FreeRTOS through 1.3.1 allows remote attackers to execute arbitrary code because of mbedTLS…
CVE-2018-16526 — High (CVSS 8.1): Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS…
CVE-2018-16525 — High (CVSS 8.1): Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS…
CVE-2018-16522 — High (CVSS 8.1): Amazon Web Services (AWS) FreeRTOS through 1.3.1 has an uninitialized pointer free in SOCKETS_SetSockOpt.
CVE-2019-13120 — High (CVSS 7.5): Amazon FreeRTOS up to and including v1.4.8 lacks length checking in prvProcessReceivedPublish, resulting in…

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