CVE-2021-21892

Exp

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.

Published: 2021-12-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-21892 is rated High Exploit Risk (93.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 30.44%, 98th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +23.29% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-21892

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-21892

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 7.15% 30.44% +23.29%
2 2025-11-21 3.75% 7.15% +3.40%
3 2025-11-18 — 3.75% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21892

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.9 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 6.0 [email protected]
9.9 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 6.0 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2021-21892

Affected software / configurations for CVE-2021-21892

Vendor Product Version Raw CPE
lantronix premierwave_2050_firmware 8.9.0.0 cpe:2.3:o:lantronix:premierwave_2050_firmware:8.9.0.0:r4:*:*:*:*:*:*

References for CVE-2021-21892

cvelogic Threat Intelligence