How severe is CVE-2021-38384?

CVE-2021-38384 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-38384 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38384?

CVE-2021-38384 affects Serverless Offline Project Serverless Offline. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-38384?

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

When was CVE-2021-38384 published?

CVE-2021-38384 was published on 2021-08-10 and last updated on 2026-06-17.

CVE-2021-38384

CVE-2021-38384 is a critical-severity vulnerability in Serverless Offline Project Serverless Offline with a CVSS 3.x base score of 9.8. 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-755.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-755
Affected product: Serverless Offline Project Serverless Offline
Published: 2021-08-10
Last modified: 2026-06-17

Description

Serverless Offline 8.0.0 returns a 403 HTTP status code for a route that has a trailing / character, which might cause a developer to implement incorrect access control, because the actual behavior within the Amazon AWS environment is a 200 HTTP status code (i.e., possibly greater than expected permissions).

Frequently asked questions

What is CVE-2021-38384?: Serverless Offline 8.0.0 returns a 403 HTTP status code for a route that has a trailing / character, which might cause a developer to implement incorrect access control, because the actual behavior within the Amazon AWS environment is a 200 HTTP status code (i.e., possibly greater than expected permissions).
How severe is CVE-2021-38384?: CVE-2021-38384 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-38384 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38384?: CVE-2021-38384 affects Serverless Offline Project Serverless Offline. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-38384?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-38384 published?: CVE-2021-38384 was published on 2021-08-10 and last updated on 2026-06-17.

References

https://github.com/dherault/serverless-offline/issues/1259

Affected products (1)

cpe:2.3:a:serverless_offline_project:serverless_offline:8.0.0:*:*:*:*:*:*:*

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