CVE-2021-47701Public exploitNetwork attack vector

Authenticated privilege escalation via unchecked permission update

Published Dec 9, 2025 · Updated Apr 7, 2026

Missing authorization in OpenBMCS 2.4 allows remote authenticated users to elevate a read account to administrator via an HTTP POST request. The update_user_permissions.php endpoint accepts attacker-supplied permission levels and a user ID without enforcing administrative authorization. Any read-level account with a valid session can grant itself full access to user administration and building-control functions.

CVSS severity8.7
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in OpenBMCS 2.4 allows remote authenticated users to elevate a read account to administrator via an HTTP POST request. The update_user_permissions.php endpoint accepts attacker-supplied permission levels and a user ID without enforcing administrative authorization. Any read-level account with a valid session can grant itself full access to user administration and building-control functions.

The record

CVE
CVE-2021-47701
Published
Dec 9, 2025
Updated
Apr 7, 2026
Vendor
OPEN BMCS
Product
OpenBMCS
Classifications
CWE-862, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 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=2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OPEN BMCS · OpenBMCSversion=2.4

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1098Account Manipulation

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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