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CVE-2021-38549

MEDIUMCVSS 5.9/10EPSS 1.29%

Last modified

CVE-2021-38549 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. MIRACASE MHUB500 USB splitters through 2021-08-09, in certain specific use cases in which the device supplies power to audio-output equipment, allow remote attackers to recover speech signals from an LED on the device, via a telescope and an electro-optical sensor, aka a "Glowworm" attack. We assume that the USB splitter supplies power to some speakers. EPSS estimates a 1.29% chance of exploitation in the next 30 days.

Description

MIRACASE MHUB500 USB splitters through 2021-08-09, in certain specific use cases in which the device supplies power to audio-output equipment, allow remote attackers to recover speech signals from an LED on the device, via a telescope and an electro-optical sensor, aka a "Glowworm" attack. We assume that the USB splitter supplies power to some speakers. The power indicator LED of the USB splitter is connected directly to the power line, as a result, the intensity of the USB splitter's power indicator LED is correlative to its power consumption. The sound played by the connected speakers affects the USB splitter's power consumption and as a result is also correlative to the light intensity of the LED. By analyzing measurements obtained from an electro-optical sensor directed at the power indicator LED of the USB splitter, we can recover the sound played by the connected speakers.

Metrics

CVSS 3.1
5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability
1.29%

66.6th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
BendaMiracase Hmub500 Firmware<= 2021-08-09

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-38549?
MIRACASE MHUB500 USB splitters through 2021-08-09, in certain specific use cases in which the device supplies power to audio-output equipment, allow remote attackers to recover speech signals from an LED on the device, via a telescope and an electro-optical sensor, aka a "Glowworm" attack. We assume that the USB splitter supplies power to some speakers. The power indicator LED of the USB splitter is connected directly to the power line, as a result, the intensity of the USB splitter's power indicator LED is correlative to its power consumption. The sound played by the connected speakers affects the USB splitter's power consumption and as a result is also correlative to the light intensity of the LED. By analyzing measurements obtained from an electro-optical sensor directed at the power indicator LED of the USB splitter, we can recover the sound played by the connected speakers.
How severe is CVE-2021-38549?
CVE-2021-38549 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 1.29% probability of exploitation in the next 30 days.
How do I fix CVE-2021-38549?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-38549?

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Source: NVD / NIST