CVE-2021-3800

Privileged file disclosure via pkexec charset alias

Published Aug 23, 2022 · Updated Aug 3, 2024

Information disclosure in GLib before 2.63.6 allows local users to read privileged files via pkexec charset alias handling. pkexec passes attacker-controlled charset aliases to GLib conversion logic, which can resolve aliases from files controlled by privileged users and expose their contents through error output. The attack requires local execution and a suitable non-UTF-8 charset condition; impact is confidential-data disclosure without reported integrity or availability impact.

CVSS severity5.5
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in GLib before 2.63.6 allows local users to read privileged files via pkexec charset alias handling. pkexec passes attacker-controlled charset aliases to GLib conversion logic, which can resolve aliases from files controlled by privileged users and expose their contents through error output. The attack requires local execution and a suitable non-UTF-8 charset condition; impact is confidential-data disclosure without reported integrity or availability impact.

The record

CVE
CVE-2021-3800
Published
Aug 23, 2022
Updated
Aug 3, 2024
Vendor
XMLSoft
Product
GLib
Classifications
CWE-200, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2022CVE 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=Fixed in glib2 2.63.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

XMLSoft · GLibversion=Fixed in glib2 2.63.6

Published CVSS scores

4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A: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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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