CVE-2021-41613

Exception-handling corruption via blocked EEAR writes

Published Apr 18, 2023 · Updated Mar 5, 2025

Register-write failure in the mor1kx processor allows context-dependent attackers to corrupt exception-handling control flow. The controller logic in mor1kx_ctrl_cappuccino.v omits an mtspr write path for EEAR, so even supervisor-mode writes leave the register unchanged. Code must execute at an authorized privilege level and invoke an exception path that rewrites EEAR; affected handlers then use stale effective-address state.

CVSS severity4.3
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Register-write failure in the mor1kx processor allows context-dependent attackers to corrupt exception-handling control flow. The controller logic in mor1kx_ctrl_cappuccino.v omits an mtspr write path for EEAR, so even supervisor-mode writes leave the register unchanged. Code must execute at an authorized privilege level and invoke an exception path that rewrites EEAR; affected handlers then use stale effective-address state.

The record

CVE
CVE-2021-41613
Published
Apr 18, 2023
Updated
Mar 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1201
Attack vector
Unavailable
Privileges
admin

Timeline

How it unfolded

  1. Apr 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

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)
VectorUnavailable
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1201Core and Compute Issues

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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