How severe is CVE-2021-21892?

CVE-2021-21892 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-2021-21892 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 30% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21892?

CVE-2021-21892 affects Lantronix Premierwave 2050 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21892?

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-2021-21892 published?

CVE-2021-21892 was published on 2021-12-22 and last updated on 2026-06-17.

CVE-2021-21892

CVE-2021-21892 is a critical-severity vulnerability in Lantronix Premierwave 2050 Firmware with a CVSS 3.x base score of 9.9. Its EPSS exploit-prediction score of 30% places it in the 98th percentile, indicating an elevated likelihood of exploitation. 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: 30% (98th 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 FsUnmount 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-2021-21892?: A stack-based buffer overflow vulnerability exists in the Web Manager FsUnmount 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-2021-21892?: CVE-2021-21892 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-2021-21892 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 30% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21892?: CVE-2021-21892 affects Lantronix Premierwave 2050 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21892?: 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-2021-21892 published?: CVE-2021-21892 was published on 2021-12-22 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1335

Affected products (1)

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

More vulnerabilities in Lantronix Premierwave 2050 Firmware

CVE-2021-21889 — Critical (CVSS 9.9): A stack-based buffer overflow vulnerability exists in the Web Manager Ping functionality of Lantronix PremierWave 2050…
CVE-2021-21883 — Critical (CVSS 9.9): An OS command injection vulnerability exists in the Web Manager Diagnostics: Ping functionality of Lantronix…
CVE-2021-21881 — Critical (CVSS 9.9): An OS command injection vulnerability exists in the Web Manager Wireless Network Scanner functionality of Lantronix…
CVE-2021-21872 — Critical (CVSS 9.9): An OS command injection vulnerability exists in the Web Manager Diagnostics: Traceroute functionality of Lantronix…
CVE-2021-21894 — Critical (CVSS 9.1): A directory traversal vulnerability exists in the Web Manager FsTFtp functionality of Lantronix PremierWave 2050…
CVE-2021-21891 — Critical (CVSS 9.1): A stack-based buffer overflow vulnerability exists in the Web Manager FsBrowseClean functionality of Lantronix…

All CVEs affecting Lantronix Premierwave 2050 Firmware →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →