CVE-2021-47688

Local allow-list bypass via pre-authorization file truncation

Published Jun 23, 2025 · Updated Jun 24, 2025

Incorrect behavior order in WhiteBeam 0.2.0 through 0.2.1 allows local users to bypass the allow-list and truncate arbitrary files. The fopen, fopen64, and truncate hooks perform truncation in OpenFileDescriptor before VerifyCanWrite authorizes the write. Local Linux access with sufficient file privileges is required; arbitrary files, including WhiteBeam startup files, can be truncated.

CVSS severity5.7
Medium
EPSS probability0.17%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect behavior order in WhiteBeam 0.2.0 through 0.2.1 allows local users to bypass the allow-list and truncate arbitrary files. The fopen, fopen64, and truncate hooks perform truncation in OpenFileDescriptor before VerifyCanWrite authorizes the write. Local Linux access with sufficient file privileges is required; arbitrary files, including WhiteBeam startup files, can be truncated.

The record

CVE
CVE-2021-47688
Published
Jun 23, 2025
Updated
Jun 24, 2025
Vendor
WhiteBeam Security, Inc.
Product
WhiteBeam
Classifications
CWE-696, T1485
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2025Record 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=0.2.0 <0.2.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

WhiteBeam Security, Inc. · WhiteBeamversion=0.2.0 <0.2.2

Published CVSS scores

5.7MITRECVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-696Incorrect Behavior Order
T1485Data Destruction

Public exploit references

No public exploit references are available in this record.

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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