How severe is CVE-2021-21242?

CVE-2021-21242 has a CVSS 3.x base score of 10.0, 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 none.

Is CVE-2021-21242 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 74% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21242?

CVE-2021-21242 affects Onedev Project Onedev. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21242?

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-2021-21242 published?

CVE-2021-21242 was published on 2021-01-15 and last updated on 2026-06-17.

CVE-2021-21242

CVE-2021-21242 is a critical-severity vulnerability in Onedev Project Onedev with a CVSS 3.x base score of 10.0. Its EPSS exploit-prediction score of 74% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v2: 7.5
EPSS exploit prediction: 74% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Onedev Project Onedev
Published: 2021-01-15
Last modified: 2026-06-17

Description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is a critical vulnerability which can lead to pre-auth remote code execution. AttachmentUploadServlet deserializes untrusted data from the `Attachment-Support` header. This Servlet does not enforce any authentication or authorization checks. This issue may lead to pre-auth remote code execution. This issue was fixed in 4.0.3 by removing AttachmentUploadServlet and not using deserialization

Frequently asked questions

What is CVE-2021-21242?: OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is a critical vulnerability which can lead to pre-auth remote code execution. AttachmentUploadServlet deserializes untrusted data from the `Attachment-Support` header. This Servlet does not enforce any authentication or authorization checks. This issue may lead to pre-auth remote code execution. This issue was fixed in 4.0.3 by removing AttachmentUploadServlet and not using deserialization
How severe is CVE-2021-21242?: CVE-2021-21242 has a CVSS 3.x base score of 10.0, 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 none.
Is CVE-2021-21242 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 74% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21242?: CVE-2021-21242 affects Onedev Project Onedev. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21242?: 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-2021-21242 published?: CVE-2021-21242 was published on 2021-01-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:onedev_project:onedev:*:*:*:*:*:*:*:*

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