CVE-2021-44850Public exploit

Code execution via unauthenticated SD boot header

Published Feb 10, 2022 · Updated Aug 4, 2024

Buffer overflow in Xilinx Zynq-7000 SoC BootROM allows physically proximate attackers to execute code via a crafted SD boot image. BootROM processes an unauthenticated register-initialization list before verifying the image signature, allowing the list to reprogram SDIO transfer controls and overwrite RAM beyond the 512-byte boot buffer. The attack requires write access to the SD boot partition or physical access to replace its media; successful exploitation bypasses secure boot and exposes protected bitstreams.

CVSS severity6.8
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Xilinx Zynq-7000 SoC BootROM allows physically proximate attackers to execute code via a crafted SD boot image. BootROM processes an unauthenticated register-initialization list before verifying the image signature, allowing the list to reprogram SDIO transfer controls and overwrite RAM beyond the 512-byte boot buffer. The attack requires write access to the SD boot partition or physical access to replace its media; successful exploitation bypasses secure boot and exposes protected bitstreams.

The record

CVE
CVE-2021-44850
Published
Feb 10, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-345, T1542.003
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
6.8NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1542.003Bootkit

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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