CVE-2021-21895Public exploitNetwork attack vector

Authenticated file overwrite via unsanitized cwd

Published Dec 22, 2021 · Updated Aug 3, 2024

Path traversal in Lantronix PremierWave 2050 8.9.0.0R4 allows remote authenticated users to overwrite arbitrary files through Web Manager. FsTFtp composes a filesystem path from the unsanitized cwd parameter, allowing traversal outside its intended /ltrx_user/ root. The user must hold the filesystem privilege and control a TFTP server; fetched content retains the destination file's permissions and can replace account or executable files.

CVSS severity9.1
Critical
EPSS probability2.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Lantronix PremierWave 2050 8.9.0.0R4 allows remote authenticated users to overwrite arbitrary files through Web Manager. FsTFtp composes a filesystem path from the unsanitized cwd parameter, allowing traversal outside its intended /ltrx_user/ root. The user must hold the filesystem privilege and control a TFTP server; fetched content retains the destination file's permissions and can replace account or executable files.

The record

CVE
CVE-2021-21895
Published
Dec 22, 2021
Updated
Aug 3, 2024
Vendor
Lantronix
Product
PremierWave 2050
Classifications
CWE-22, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Lantronix · PremierWave 2050version=Lantronix PremierWave 2050 8.9.0.0R4 (in QEMU)

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
9.1Cisco TalosCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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