CVE-2021-33478
No known exploitation. EPSS puts it in the 21st percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.3% chance of exploitation activity in the next 30 days, which ranks it in the 21st percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
5 events over 1218 days, from the signal feeds we watch.
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
- Cisco IP Phone 8800 Series with MultiplatformNetworking Infrastructure
- Cisco IP Phone 8811 with MultiplatformNetworking Infrastructure
- Cisco IP Phone 8811Networking Infrastructure
- Cisco IP Phone 8841 with MultiplatformNetworking Infrastructure
- Cisco IP Phone 8841Networking Infrastructure
- Cisco IP Phone 8851 with MultiplatformNetworking Infrastructure
- Cisco IP Phone 8851Networking Infrastructure
- Cisco IP Phone 8861Networking Infrastructure
And 23 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Scored 6.8 by NVD.
How it is reached
- Attack Vector PhysicalRequires physical access to the device
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
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