CVE-2023-53481Public exploit

Local service interruption via UBI retry loop

Published Oct 1, 2025 · Updated Oct 1, 2025

An infinite loop in the Linux UBI wear-leveling path allows local users to hang a UBIFS background thread after a flash read fault. During concurrent unmapping, wear_leveling_worker deletes a lookup entry and clears move pointers; ubi_wl_put_peb() then treats two NULL pointers as equal and retries forever. Reachability requires a UBI-backed UBIFS volume and a wear-leveling read failure, while the observed consequence is one background thread consuming 100% CPU.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An infinite loop in the Linux UBI wear-leveling path allows local users to hang a UBIFS background thread after a flash read fault. During concurrent unmapping, wear_leveling_worker deletes a lookup entry and clears move pointers; ubi_wl_put_peb() then treats two NULL pointers as equal and retries forever. Reachability requires a UBI-backed UBIFS volume and a wear-leveling read failure, while the observed consequence is one background thread consuming 100% CPU.

The record

CVE
CVE-2023-53481
Published
Oct 1, 2025
Updated
Oct 1, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-835, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 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=2.6.25
  2. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <3afaaf6f5867dc4ad383808d4053f428ec7b867d
  3. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <4d57a7333e26040f2b583983e1970d9d460e56b0
  4. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <5af1c643184a5d09ff5b3f334077a4d0a163c677
  5. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <8a18856e074479bd050b01e688c58defadce7ab0
  6. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <b40d2fbf47af58377e898b5062077a47bb28a132
  7. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <b5be23f6ae610bdb262160a1f294afee6d0e6a69
  8. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <cc4bc532acda66189bddc03b3fe1ad689d9a48a2
  9. Affected versionversion=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <f006f596fe851c3b6aae60b79f89f89f0e515d2f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.25; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <3afaaf6f5867dc4ad383808d4053f428ec7b867d; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <4d57a7333e26040f2b583983e1970d9d460e56b0; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <5af1c643184a5d09ff5b3f334077a4d0a163c677; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <8a18856e074479bd050b01e688c58defadce7ab0; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <b40d2fbf47af58377e898b5062077a47bb28a132; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <b5be23f6ae610bdb262160a1f294afee6d0e6a69; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <cc4bc532acda66189bddc03b3fe1ad689d9a48a2; version=43f9b25a9cdd7b177f77f026b1461abd1abbd174 <f006f596fe851c3b6aae60b79f89f89f0e515d2f

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5NIST NVDCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
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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