CVE-2021-33478

mediumpriority · track · 27EPSS 0.003 · 23 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.30% (23rd) EPSS
CVSS 4.6 · medium
Is it mine?
32 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

The TrustZone implementation in certain Broadcom MediaxChange firmware could allow an unauthenticated, physically proximate attacker to achieve arbitrary code execution in the TrustZone Trusted Execution Environment (TEE) of an affected device. This, for example, affects certain Cisco IP Phone and Wireless IP Phone products before 2021-07-07. Exploitation is possible only when the attacker can disassemble the device in order to control the voltage/current for chip pins.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

6.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.6mediumAV:L/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 6.4
v3.16.8mediumCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 0.9 · impact 5.9
v3.16.8mediumAV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.16.2mediumCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.16.8mediumCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · Cisco PSIRT US
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-119USprimaryCWE-119USCWE-120US
04

affected products (32)

Products and version ranges known to be affected.

showing 20 of 32
05

advisories (1)

Vendor and ecosystem advisories describing this.

  • cisco-sa-brcm-mxc-jul2021-26LqUZUhBroadcom MediaxChange Vulnerability Affecting Cisco Products: July 20212021-07-07csaf · cisco_csafUS

    A vulnerability in the TrustZone implementation in certain Broadcom MediaxChange firmware was reported by security researchers. To exploit this vulnerability on the affected Cisco products, the attacker would need to dismount the backplate of the device and trigger a specific series of impulses on the chipset. This would reload the device in a special mode allowing access to the bootshell. The attacker would then issue specific commands with crafted parameters in the bootshell, which would trigger the vulnerability. Exploitation of this vulnerability could result in arbitrary code execution with privilege escalation. At the time of publication, a link to the details about this vulnerability was not available.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisco_csafnvdNVDCVE.orgMITRE
published 2021-07-22modified 2026-06-17
09

references (6)

External citations — patches, advisories, analysis.

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