CVE-2023-53487

Kernel crash via unmarked flash cache usercopy

Published Oct 1, 2025 · Updated Oct 1, 2025

Denial of service in the Linux powerpc RTAS flash component allows local users to crash the kernel through the firmware-update interface. rtas_flash_write copies firmware blocks from user memory into flash_block_cache objects that were not marked as usercopy-safe, causing hardened usercopy to abort. Reachability requires a powerpc RTAS system, hardened usercopy, and access to /proc/powerpc/rtas/firmware_update; the demonstrated consequence is a kernel BUG and service interrupt.

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

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in the Linux powerpc RTAS flash component allows local users to crash the kernel through the firmware-update interface. rtas_flash_write copies firmware blocks from user memory into flash_block_cache objects that were not marked as usercopy-safe, causing hardened usercopy to abort. Reachability requires a powerpc RTAS system, hardened usercopy, and access to /proc/powerpc/rtas/firmware_update; the demonstrated consequence is a kernel BUG and service interrupt.

The record

CVE
CVE-2023-53487
Published
Oct 1, 2025
Updated
Oct 1, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.16
  2. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <0ba7f969be599e21d4b1f1e947593de6515f4996
  3. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <1d29e21ed09fa668416fa7721e08d451b9903485
  4. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <4f3175979e62de3b929bfa54a0db4b87d36257a7
  5. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <6acb8a453388374fafb3c3b37534b675b2aa0ae1
  6. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <8ef25fb13494e35c6dbe15445c7875fa92bc3e8b
  7. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <8f09cc15dcd91d16562400c51d24c7be0d5796fa
  8. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <b8fee83aa4ed3846c7f50a0b364bc699f48d96e5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <0ba7f969be599e21d4b1f1e947593de6515f4996; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <1d29e21ed09fa668416fa7721e08d451b9903485; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <4f3175979e62de3b929bfa54a0db4b87d36257a7; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <6acb8a453388374fafb3c3b37534b675b2aa0ae1; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <8ef25fb13494e35c6dbe15445c7875fa92bc3e8b; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <8f09cc15dcd91d16562400c51d24c7be0d5796fa; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <b8fee83aa4ed3846c7f50a0b364bc699f48d96e5

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo