CVE-2021-28210

Firmware service interruption via unbounded section recursion

Published Jun 11, 2021 · Updated Aug 3, 2024

Uncontrolled recursion in TianoCore EDK II through edk2-stable202008 allows remote attackers to cause a firmware service interruption. DxeCore's FindChildNode() recursively descends nested firmware-volume encapsulation sections without enforcing a nesting-depth limit, exhausting available resources. Exploitation requires crafted firmware-volume contents to reach DxeCore through an installed Firmware Volume Block2 instance or ProcessFirmwareVolume().

CVSS severity7.8
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in TianoCore EDK II through edk2-stable202008 allows remote attackers to cause a firmware service interruption. DxeCore's FindChildNode() recursively descends nested firmware-volume encapsulation sections without enforcing a nesting-depth limit, exhausting available resources. Exploitation requires crafted firmware-volume contents to reach DxeCore through an installed Firmware Volume Block2 instance or ProcessFirmwareVolume().

The record

CVE
CVE-2021-28210
Published
Jun 11, 2021
Updated
Aug 3, 2024
Vendor
TianoCore
Product
EDK II
Classifications
CWE-674, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 11, 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=unspecified <=edk2-stable202008

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

TianoCore · EDK IIversion=unspecified <=edk2-stable202008

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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