How severe is CVE-2021-33838?

CVE-2021-33838 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-33838 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33838?

CVE-2021-33838 affects Luca-app Luca. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33838?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-33838 published?

CVE-2021-33838 was published on 2021-06-04 and last updated on 2026-06-17.

CVE-2021-33838

CVE-2021-33838 is a high-severity vulnerability in Luca-app Luca with a CVSS 3.x base score of 7.5. 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-203.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Affected product: Luca-app Luca
Published: 2021-06-04
Last modified: 2026-06-17

Description

Luca through 1.7.4 on Android allows remote attackers to obtain sensitive information about COVID-19 tracking because requests related to Check-In State occur shortly after requests for Phone Number Registration.

Frequently asked questions

What is CVE-2021-33838?: Luca through 1.7.4 on Android allows remote attackers to obtain sensitive information about COVID-19 tracking because requests related to Check-In State occur shortly after requests for Phone Number Registration.
How severe is CVE-2021-33838?: CVE-2021-33838 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-33838 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33838?: CVE-2021-33838 affects Luca-app Luca. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33838?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-33838 published?: CVE-2021-33838 was published on 2021-06-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:luca-app:luca:*:*:*:*:*:android:*:*

More vulnerabilities in Luca-app Luca

CVE-2021-33840 — High (CVSS 7.5): The server in Luca through 1.1.14 allows remote attackers to cause a denial of service (insertion of many fake records…
CVE-2021-33839 — High (CVSS 7.5): Luca through 1.7.4 on Android allows remote attackers to obtain sensitive information about COVID-19 tracking because…

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CVE-2024-25714 — Critical (CVSS 9.8): In Rhonabwy through 1.1.13, HMAC signature verification uses a strcmp function that is vulnerable to side-channel…
CVE-2024-25191 — Critical (CVSS 9.8): php-jwt 1.0.0 uses strcmp (which is not constant time) to verify authentication, which makes it easier to bypass…
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