PatchTheCVECVE-2021-38545: Raspberry Pi 3 B+ and 4 B devices through 2021-08-09, in certain specific use cases in which the device suppli
CVE-2021-38545 is a medium-severity flaw (CVSS 5.9) affecting raspberry pi 4 model b firmware, raspberry pi 3 model b\+ firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Raspberry Pi 3 B+ and 4 B devices 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 Raspberry Pi supplies power to some speakers. The power indicator LED of the Raspberry Pi is connected directly to the power line, as a r
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.3% (top 30%) |
| CISA exploited list | No |
| Published | 2021-08-11 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-38545?
raspberry pi 4 model b firmware: upgrade to newer than 2021-08-09; raspberry pi 3 model b\+ firmware: upgrade to newer than 2021-08-09. Exact commands for each OS are on this page.
Is CVE-2021-38545 being exploited?
CVE-2021-38545 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-38545 affect?
CVE-2021-38545 affects raspberry pi 4 model b firmware, raspberry pi 3 model b\+ firmware. Severity is medium (CVSS 5.9). Raspberry Pi 3 B+ and 4 B devices 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 an
How urgent is CVE-2021-38545?
Priority 48/100. Public exploit reference; Remotely exploitable, no login, no user action