How severe is CVE-2021-21889?

CVE-2021-21889 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-21889 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21889?

CVE-2021-21889 affects Lantronix Premierwave 2050 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21889?

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

When was CVE-2021-21889 published?

CVE-2021-21889 was published on 2021-12-22 and last updated on 2026-06-17.

CVE-2021-21889

CVE-2021-21889 is a critical-severity vulnerability in Lantronix Premierwave 2050 Firmware with a CVSS 3.x base score of 9.9. 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: Critical (CVSS 3.x base score 9.9)
CVSS v2: 6.5
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Lantronix Premierwave 2050 Firmware
Published: 2021-12-22
Last modified: 2026-06-17

Description

A stack-based buffer overflow vulnerability exists in the Web Manager Ping functionality of Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU). A specially crafted HTTP request can lead to remote code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.

Frequently asked questions

What is CVE-2021-21889?: A stack-based buffer overflow vulnerability exists in the Web Manager Ping functionality of Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU). A specially crafted HTTP request can lead to remote code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.
How severe is CVE-2021-21889?: CVE-2021-21889 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21889 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21889?: CVE-2021-21889 affects Lantronix Premierwave 2050 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21889?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-21889 published?: CVE-2021-21889 was published on 2021-12-22 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1333

Affected products (1)

cpe:2.3:o:lantronix:premierwave_2050_firmware:8.9.0.0:r4:*:*:*:*:*:*

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CVE-2021-21881 — Critical (CVSS 9.9): An OS command injection vulnerability exists in the Web Manager Wireless Network Scanner functionality of Lantronix…
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