CVE-2021-21242

CRITICALNVD 10.010.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 10.0 under NVD CVSS v3. EPSS exploit probability: 74.2%, top 1% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
10.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 74%
CISA-KEV: Not listedEPSS PROB: 74%CVSS: 10.0Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
10.0
EG Score
10.0(medium)
EG Risk
79(Track*)
EG Risk 79/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity100% × 45%
Exploitation74% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
74%
EPSS %ILE
99%
KEV
Not listed

Published

January 15, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Sep 19, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Pre-Auth Unsafe Deserialization on AttachmentUploadServet · Advisory · theonedev/onedev · GitHub

Affected: 4.0.3 by removing AttachmentUploadServlet and not using deserialization

https://github.com/theonedev/onedev/security/advisories/GHSA-5q3q-f373-2jv8
github_commit Patch Available

commit f864053176c0 (theonedev/onedev)

Patch available: theonedev/onedev v16.2.0 (contains commit f864053176c0)

https://github.com/theonedev/onedev/commit/f864053176c08f59ef2d97fea192ceca46a4d9be

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 21× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 107 total refreshes for this CVE.

  1. 2026-09-18 19:23 UTCEPSS rescore
  2. 2026-09-17 19:23 UTCEPSS rescore
  3. 2026-09-16 14:05 UTCEPSS rescore
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  11. 2026-09-07 00:19 UTCOSV refresh
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  22. 2026-08-20 10:01 UTCOSV refresh
  23. 2026-08-19 17:01 UTCEPSS rescore
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  1. 2026-08-13 21:57 UTCEPSS rescore
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  4. 2026-08-07 16:23 UTCEPSS rescore
  5. 2026-08-05 19:14 UTCEPSS rescore
  6. 2026-08-05 05:40 UTCOSV refresh
  7. 2026-08-02 02:24 UTCEPSS rescore
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  9. 2026-07-30 16:25 UTCEPSS rescore
  10. 2026-07-25 14:15 UTCEPSS rescore
  11. 2026-07-24 14:15 UTCEPSS rescore
  12. 2026-07-23 01:57 UTCEG score recompute
  13. 2026-07-22 22:43 UTCEG score recompute
  14. 2026-07-22 14:05 UTCEPSS rescore
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  18. 2026-07-19 14:28 UTCEPSS rescore
  19. 2026-07-19 03:52 UTCOSV refresh
  20. 2026-07-15 16:55 UTCEPSS rescore
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  22. 2026-07-13 06:10 UTCEPSS rescore
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  24. 2026-07-11 08:25 UTCEPSS rescore
  25. 2026-07-07 13:43 UTCEPSS rescore
  26. 2026-07-05 02:28 UTCEPSS rescore
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  28. 2026-07-02 16:57 UTCEPSS rescore
  29. 2026-07-01 15:03 UTCEPSS rescore
  30. 2026-07-01 10:48 UTCOSV refresh
  31. 2026-06-29 14:04 UTCEPSS rescore
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  40. 2026-06-23 21:31 UTCEPSS rescore
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  42. 2026-06-21 14:54 UTCEPSS rescore
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  44. 2026-06-18 17:51 UTCEPSS rescore
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  47. 2026-06-15 17:46 UTCEPSS rescore
  48. 2026-06-14 23:15 UTCEPSS rescore
  49. 2026-06-13 22:58 UTCEPSS rescore
  50. 2026-06-13 16:13 UTCOSV refresh
  51. 2026-06-12 23:10 UTCEPSS rescore
  52. 2026-06-12 23:10 UTCEPSS rescore
  53. 2026-06-11 13:58 UTCEPSS rescore
  54. 2026-06-10 22:16 UTCEPSS rescore
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  59. 2026-06-05 22:45 UTCEPSS rescore
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  73. 2026-05-29 13:42 UTCEPSS rescore
  74. 2026-05-28 13:43 UTCEPSS rescore
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Frequently asked(5)

What is CVE-2021-21242?
CVE-2021-21242 is a critical vulnerability published on January 15, 2021. 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…
When was CVE-2021-21242 disclosed?
CVE-2021-21242 was first published in the National Vulnerability Database on January 15, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-21242 actively exploited?
CVE-2021-21242 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 74% probability of exploitation in the next 30 days, which ranks it in the top 0.5% of all scored CVEs.
What is the CVSS score of CVE-2021-21242?
CVE-2021-21242 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2021-21242?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21242, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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