CVE-2021-3802Public exploit

Kernel panic via attacker-controlled ext error policy

Published Nov 29, 2021 · Updated Aug 3, 2024

Improper input validation in UDisks before 2.9.4 allows local users to trigger a kernel panic by mounting a crafted ext filesystem image. Its ext2/3/4 mount helpers honor the attacker-controlled s_errors superblock field instead of forcing errors=remount-ro, so an injected filesystem error selects panic behavior. An unprivileged user able to mount an image through udisksctl or an automounting desktop or embedded system can halt the Linux host.

CVSS severity4.2
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in UDisks before 2.9.4 allows local users to trigger a kernel panic by mounting a crafted ext filesystem image. Its ext2/3/4 mount helpers honor the attacker-controlled s_errors superblock field instead of forcing errors=remount-ro, so an injected filesystem error selects panic behavior. An unprivileged user able to mount an image through udisksctl or an automounting desktop or embedded system can halt the Linux host.

The record

CVE
CVE-2021-3802
Published
Nov 29, 2021
Updated
Aug 3, 2024
Vendor
Storaged Project
Product
UDisks
Classifications
CWE-20, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 29, 2021CVE 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=udisks-2.9.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Storaged Project · UDisksversion=udisks-2.9.4

Published CVSS scores

4.2NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:H
6.3NIST NVDAV:N/AC:M/Au:S/C:N/I:N/A:C

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

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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