CVE-2021-45840Public exploitNetwork attack vector

Unauthenticated root command execution via shell interpolation

Published Apr 25, 2022 · Updated Aug 4, 2024

Command injection in TerraMaster TOS 4.2.15-2107141517 allows remote attackers to execute arbitrary commands as root through its web interface. The app_start_stop action interpolates attacker-controlled input into a command passed to shell_exec() or system() without shell escaping. Disclosed information and predictable session tokens allow an unauthenticated network client to forge an administrator session before invoking the endpoint.

CVSS severity9.8
Critical
EPSS probability3.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in TerraMaster TOS 4.2.15-2107141517 allows remote attackers to execute arbitrary commands as root through its web interface. The app_start_stop action interpolates attacker-controlled input into a command passed to shell_exec() or system() without shell escaping. Disclosed information and predictable session tokens allow an unauthenticated network client to forge an administrator session before invoking the endpoint.

The record

CVE
CVE-2021-45840
Published
Apr 25, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 25, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

10.0NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1059.004Command and Scripting Interpreter: Unix Shell

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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