CVE-2020-27208
CVE-2020-27208 is a medium-severity vulnerability in Solokeys Solo Firmware with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-326.
Key facts
- Severity: Medium (CVSS 3.x base score 6.8)
- CVSS v2: 4.6
- EPSS exploit prediction: 0% (25th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-326
- Affected product: Solokeys Solo Firmware
- Published:
- Last modified:
Description
The flash read-out protection (RDP) level is not enforced during the device initialization phase of the SoloKeys Solo 4.0.0 & Somu and the Nitrokey FIDO2 token. This allows an adversary to downgrade the RDP level and access secrets such as private ECC keys from SRAM via the debug interface.
Frequently asked questions
- What is CVE-2020-27208?
- The flash read-out protection (RDP) level is not enforced during the device initialization phase of the SoloKeys Solo 4.0.0 & Somu and the Nitrokey FIDO2 token. This allows an adversary to downgrade the RDP level and access secrets such as private ECC keys from SRAM via the debug interface.
- How severe is CVE-2020-27208?
- CVE-2020-27208 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2020-27208 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-27208?
- CVE-2020-27208 primarily affects Solokeys Solo Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-27208?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2020-27208 published?
- CVE-2020-27208 was published on 2021-05-21 and last updated on 2026-06-17.
References
- https://eprint.iacr.org/2021/640
- https://github.com/solokeys/solo/commit/a9c02cd354f34b48195a342c7f524abdef5cbcec
- https://solokeys.com
- https://twitter.com/SoloKeysSec
- https://www.aisec.fraunhofer.de/de/das-institut/wissenschaftliche-exzellenz/security-and-trust-in-open-source-security-tokens.html
- https://www.aisec.fraunhofer.de/en/FirmwareProtection.html
Affected products (3)
- cpe:2.3:o:solokeys:solo_firmware:4.0.0:*:*:*:*:*:*:*
- cpe:2.3:o:solokeys:somu_firmware:-:*:*:*:*:*:*:*
- cpe:2.3:o:nitrokey:fido2_firmware:-:*:*:*:*:*:*:*
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