CVE-2021-47903Public exploitNetwork attack vectorHinoki check available

Authenticated code execution via external app Command field

Published Jan 23, 2026 · Updated Jan 23, 2026

OS command injection in LiteSpeed Web Server Enterprise 5.4.11 allows remote authenticated users to execute arbitrary shell commands. The WebAdmin confMgr.php handler accepts a path value from the external-app Command field and passes traversal sequences plus shell syntax into process startup without adequate validation. Administrative WebAdmin access and a graceful restart are required; the injected program then runs with the configured external-app account's privileges.

CVSS severity8.6
High
EPSS probability1.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

OS command injection in LiteSpeed Web Server Enterprise 5.4.11 allows remote authenticated users to execute arbitrary shell commands. The WebAdmin confMgr.php handler accepts a path value from the external-app Command field and passes traversal sequences plus shell syntax into process startup without adequate validation. Administrative WebAdmin access and a graceful restart are required; the injected program then runs with the configured external-app account's privileges.

The record

CVE
CVE-2021-47903
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
LiteSpeed Technologies
Product
LiteSpeed Web Server
Classifications
CWE-78, T1059.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record 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=5.4.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

LiteSpeed Technologies · LiteSpeed Web Serverversion=5.4.11

Published CVSS scores

8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.6VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
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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