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CVE-2021-38543

19
FAUCET Score

CVE-2021-38543 describes a "Glowworm" attack affecting TP-Link UE330 USB splitter devices. This vulnerability allows remote attackers to recover speech signals from audio-output equipment powered by the splitter by analyzing the light intensity of the device's power indicator LED. The attack requires specific conditions, including the device supplying power to speakers and the use of a telescope and electro-optical sensor. The vulnerability has a CVSS score of 5.9 (Medium), indicating a network-based attack with high complexity and high confidentiality impact, but no integrity or availability impact. The attack relies on the correlation between the LED's light intensity and the device's power consumption, which is influenced by the sound played through connected speakers. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) is available. Community discussion and media coverage for this CVE are minimal, suggesting low public awareness and attention.

Impacted Technologies

VendorProductVersion(s)CPE
<= 2021-08-09CPE matchmatch criteria
cpe:2.3:o:tp-link:ue330_firmware:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

5.9MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
2.2
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.29%
Probability of exploitation in next 30 days
EPSS Percentile
67.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0129 is in the 36th percentile among its peer group of 19,955 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

nassiben.com / glowworm-attack
ExploitThird Party Advisory