CVE-2014-4859Public exploit

Firmware code execution via undersized capsule buffer

Published Jan 31, 2020 · Updated Aug 6, 2024

Integer overflow in Phoenix SecureCore Technology 3.0 before May 23, 2014 allows local users to execute code in system firmware. During DXE capsule processing, a crafted capsule size wraps, causing an undersized buffer allocation before attacker-controlled capsule data is copied past its bounds. Exploitation requires authenticated local access to the capsule-update interface and can install persistent firmware code, bypass Secure Boot, or render the platform unusable.

CVSS severity6.8
Medium
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Phoenix SecureCore Technology 3.0 before May 23, 2014 allows local users to execute code in system firmware. During DXE capsule processing, a crafted capsule size wraps, causing an undersized buffer allocation before attacker-controlled capsule data is copied past its bounds. Exploitation requires authenticated local access to the capsule-update interface and can install persistent firmware code, bypass Secure Boot, or render the platform unusable.

The record

CVE
CVE-2014-4859
Published
Jan 31, 2020
Updated
Aug 6, 2024
Vendor
Phoenix Technologies
Product
Phoenix SecureCore Technology 3.0
Classifications
CWE-190, T1068, T1542.001
Attack vector
physical
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 31, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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=before 5/23/2014

What conditions does exploitation require?

Attack vectorphysical
Required privilegesauthenticated

What is affected?

Phoenix Technologies · Phoenix SecureCore Technology 3.0version=before 5/23/2014

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
6.8NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.4CERT/CCAV:L/AC:H/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C
6.0CERT/CCAV:L/AC:H/Au:S/C:C/I:C/A:C

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)
Vectorphysical
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1068Exploitation for Privilege Escalation
T1542.001Pre-OS Boot System Firmware

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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