How severe is CVE-2021-45933?

CVE-2021-45933 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-45933 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45933?

CVE-2021-45933 affects Wolfssl Wolfmqtt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45933?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-45933 published?

CVE-2021-45933 was published on 2022-01-01 and last updated on 2026-06-17.

CVE-2021-45933

CVE-2021-45933 is a medium-severity vulnerability in Wolfssl Wolfmqtt with a CVSS 3.x base score of 5.5. 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-787.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Wolfssl Wolfmqtt
Published: 2022-01-01
Last modified: 2026-06-17

Description

wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow (8 bytes) in MqttDecode_Publish (called from MqttClient_DecodePacket and MqttClient_HandlePacket).

Frequently asked questions

What is CVE-2021-45933?: wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow (8 bytes) in MqttDecode_Publish (called from MqttClient_DecodePacket and MqttClient_HandlePacket).
How severe is CVE-2021-45933?: CVE-2021-45933 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-45933 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45933?: CVE-2021-45933 affects Wolfssl Wolfmqtt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45933?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-45933 published?: CVE-2021-45933 was published on 2022-01-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:wolfssl:wolfmqtt:1.9:*:*:*:*:*:*:*

More vulnerabilities in Wolfssl Wolfmqtt

CVE-2021-45939 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttClient_DecodePacket (called from MqttClient_WaitType and…
CVE-2021-45938 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttClient_DecodePacket (called from MqttClient_WaitType and…
CVE-2021-45937 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttClient_DecodePacket (called from MqttClient_WaitType and…
CVE-2021-45936 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttDecode_Disconnect (called from MqttClient_DecodePacket and…
CVE-2021-45934 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttClient_DecodePacket (called from MqttClient_HandlePacket…
CVE-2021-45932 — Medium (CVSS 5.5): wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow (4 bytes) in MqttDecode_Publish (called from…

All CVEs affecting Wolfssl Wolfmqtt →

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