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
Trending — 3 sources updated this weekElevated
10.0
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 74%
CISA-KEV: Not listedEPSS: 74%CVSS: 10.0Exploit: NoneExposed: 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
99.4%
KEV
Not listed

Published

January 15, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Jul 18, 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 v14.1.9 (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 8× in last 7d / 30× 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.

  1. 2026-07-23 01:57 UTCEG score recompute
  2. 2026-07-22 22:43 UTCEG score recompute
  3. 2026-07-22 14:05 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-21 15:22 UTCEPSS rescore
  6. 2026-07-20 17:04 UTCEPSS rescore
  7. 2026-07-19 14:28 UTCEPSS rescore
  8. 2026-07-19 03:52 UTCOSV refresh
  9. 2026-07-15 16:55 UTCEPSS rescore
  10. 2026-07-15 16:55 UTCEPSS rescore
  11. 2026-07-13 06:10 UTCEPSS rescore
  12. 2026-07-13 06:10 UTCEPSS rescore
  13. 2026-07-11 08:25 UTCEPSS rescore
  14. 2026-07-07 13:43 UTCEPSS rescore
  15. 2026-07-05 02:28 UTCEPSS rescore
  16. 2026-07-05 02:28 UTCEPSS rescore
  17. 2026-07-02 16:57 UTCEPSS rescore
  18. 2026-07-01 15:03 UTCEPSS rescore
  19. 2026-07-01 10:48 UTCOSV refresh
  20. 2026-06-29 14:04 UTCEPSS rescore
  21. 2026-06-29 14:04 UTCEPSS rescore
  22. 2026-06-28 14:05 UTCEPSS rescore
  23. 2026-06-27 03:06 UTCEPSS rescore
  24. 2026-06-27 03:06 UTCEPSS rescore
  25. 2026-06-25 13:48 UTCEPSS rescore
Show 46 more
  1. 2026-06-25 13:48 UTCEPSS rescore
  2. 2026-06-24 14:03 UTCEPSS rescore
  3. 2026-06-24 14:03 UTCEPSS rescore
  4. 2026-06-23 21:31 UTCEPSS rescore
  5. 2026-06-23 21:31 UTCEPSS rescore
  6. 2026-06-21 14:54 UTCEPSS rescore
  7. 2026-06-21 14:54 UTCEPSS rescore
  8. 2026-06-18 17:51 UTCEPSS rescore
  9. 2026-06-18 17:51 UTCEPSS rescore
  10. 2026-06-17 17:51 UTCEPSS rescore
  11. 2026-06-15 17:46 UTCEPSS rescore
  12. 2026-06-14 23:15 UTCEPSS rescore
  13. 2026-06-13 22:58 UTCEPSS rescore
  14. 2026-06-13 16:13 UTCOSV refresh
  15. 2026-06-12 23:10 UTCEPSS rescore
  16. 2026-06-12 23:10 UTCEPSS rescore
  17. 2026-06-11 13:58 UTCEPSS rescore
  18. 2026-06-10 22:16 UTCEPSS rescore
  19. 2026-06-10 22:16 UTCEPSS rescore
  20. 2026-06-10 13:20 UTCEPSS rescore
  21. 2026-06-08 14:15 UTCEPSS rescore
  22. 2026-06-08 14:15 UTCEPSS rescore
  23. 2026-06-05 22:45 UTCEPSS rescore
  24. 2026-06-05 22:45 UTCEPSS rescore
  25. 2026-06-05 06:09 UTCEPSS rescore
  26. 2026-06-05 06:09 UTCEPSS rescore
  27. 2026-06-05 06:08 UTCEPSS rescore
  28. 2026-06-04 13:10 UTCEPSS rescore
  29. 2026-06-02 20:11 UTCEPSS rescore
  30. 2026-06-02 20:11 UTCEPSS rescore
  31. 2026-06-01 13:50 UTCEPSS rescore
  32. 2026-06-01 13:50 UTCEPSS rescore
  33. 2026-05-31 22:29 UTCEPSS rescore
  34. 2026-05-31 22:29 UTCEPSS rescore
  35. 2026-05-31 00:15 UTCEPSS rescore
  36. 2026-05-31 00:15 UTCEPSS rescore
  37. 2026-05-29 13:42 UTCEPSS rescore
  38. 2026-05-28 13:43 UTCEPSS rescore
  39. 2026-05-28 13:43 UTCEPSS rescore
  40. 2026-05-26 22:02 UTCEG score recompute
  41. 2026-05-26 13:42 UTCEPSS rescore
  42. 2026-05-26 13:42 UTCEPSS rescore
  43. 2026-05-26 07:17 UTCEPSS rescore
  44. 2026-05-26 07:17 UTCEPSS rescore
  45. 2026-05-24 20:42 UTCOSV refresh
  46. 2026-05-24 16:49 UTCEPSS rescore

Related CVEs(same CWE)

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 99.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-21242

Explore →

Is Your Infrastructure Affected by CVE-2021-21242?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs