CVE-2021-47652

System crash via uninitialized framebuffer modelist destruction

Published Feb 26, 2025 · Updated May 11, 2026

A NULL pointer dereference in the Linux kernel allows local users to crash the system during an SMSC UFX USB display probe. ufx_usb_probe() calls fb_destroy_modelist() after fb_alloc_cmap() fails, although the modelist has not yet been initialized. Reaching the fault requires the SMSC UFX framebuffer driver probe and a color-map allocation failure; the reported consequence is a kernel NULL dereference and service interruption.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A NULL pointer dereference in the Linux kernel allows local users to crash the system during an SMSC UFX USB display probe. ufx_usb_probe() calls fb_destroy_modelist() after fb_alloc_cmap() fails, although the modelist has not yet been initialized. Reaching the fault requires the SMSC UFX framebuffer driver probe and a color-map allocation failure; the reported consequence is a kernel NULL dereference and service interruption.

The record

CVE
CVE-2021-47652
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=3.2
  2. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <0fd28daec73525382e5c992db8743bf76e42cd5c
  3. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <1791f487f877a9e83d81c8677bd3e7b259e7cb27
  4. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <64ec3e678d76419f207b9cdd338dda438ca10b1c
  5. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <9280ef235b05e8f19f8bc6d547b992f0a0ef398d
  6. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <c420b540db4b5d69de0a36d8b9d9a6a79a04f05a
  7. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <d1b6a1f0c23b7164250479bf92e2893291dca539
  8. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <d396c651e2b508b6179bb678cc029f3becbf5170
  9. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <da8b269cc0a2526ebeaccbe2484c999eb0f822cf
  10. Affected versionversion=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <dd3a6cc7385b89ec2303f39dfc3bafa4e24cec4b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.2; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <0fd28daec73525382e5c992db8743bf76e42cd5c; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <1791f487f877a9e83d81c8677bd3e7b259e7cb27; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <64ec3e678d76419f207b9cdd338dda438ca10b1c; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <9280ef235b05e8f19f8bc6d547b992f0a0ef398d; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <c420b540db4b5d69de0a36d8b9d9a6a79a04f05a; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <d1b6a1f0c23b7164250479bf92e2893291dca539; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <d396c651e2b508b6179bb678cc029f3becbf5170; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <da8b269cc0a2526ebeaccbe2484c999eb0f822cf; version=3c8a63e22a0802fd56380f6ab305b419f18eb6f5 <dd3a6cc7385b89ec2303f39dfc3bafa4e24cec4b

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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