CVE-2021-29437

HIGHNVD 8.08.0—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.0 under NVD CVSS v3. EPSS exploit probability: 0.8%, top 47% 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
8.0
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.0Exploit: NoneExposed: 0

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

ScratchOAuth2 is an Oauth implementation for Scratch. Any ScratchOAuth2-related data normally accessible and modifiable by a user can be read and modified by a third party. 1. Scratch user visits 3rd party site. 2. 3rd party site asks user for Scratch username. 3. 3rd party site pretends to be user and gets login code from ScratchOAuth2. 4. 3rd party site gives code to user and instructs them to post it on their profile. 5. User posts code on their profile, not knowing it is a ScratchOAuth2 login code. 6. 3rd party site completes login with ScratchOAuth2. 7. 3rd party site has full access to anything the user could do if they directly logged in. See referenced GitHub security advisory for patch notes and workarounds.

CVSS v3
8.0
EG Score
8.0(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity80% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
53.0%
KEV
Not listed

Published

April 13, 2021

Last Modified

November 21, 2024

References (4)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 48× 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 103 total refreshes for this CVE.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 01:59 UTCEG score recompute
  4. 2026-07-22 22:46 UTCEG score recompute
  5. 2026-07-22 14:06 UTCEPSS rescore
  6. 2026-07-22 14:06 UTCEPSS rescore
  7. 2026-07-21 15:22 UTCEPSS rescore
  8. 2026-07-21 15:22 UTCEPSS rescore
  9. 2026-07-20 17:05 UTCEPSS rescore
  10. 2026-07-19 14:28 UTCEPSS rescore
  11. 2026-07-19 02:27 UTCEPSS rescore
  12. 2026-07-19 02:27 UTCEPSS rescore
  13. 2026-07-18 10:02 UTCEPSS rescore
  14. 2026-07-18 10:02 UTCEPSS rescore
  15. 2026-07-16 17:00 UTCEPSS rescore
  16. 2026-07-15 16:55 UTCEPSS rescore
  17. 2026-07-15 16:55 UTCEPSS rescore
  18. 2026-07-15 01:58 UTCEPSS rescore
  19. 2026-07-13 22:27 UTCEPSS rescore
  20. 2026-07-13 22:27 UTCEPSS rescore
  21. 2026-07-13 06:10 UTCEPSS rescore
  22. 2026-07-13 03:37 UTCOSV refresh
  23. 2026-07-12 05:44 UTCEPSS rescore
  24. 2026-07-12 05:44 UTCEPSS rescore
  25. 2026-07-11 08:25 UTCEPSS rescore
Show 75 more
  1. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-09 19:07 UTCEPSS rescore
  3. 2026-07-08 15:12 UTCEPSS rescore
  4. 2026-07-07 13:43 UTCEPSS rescore
  5. 2026-07-06 16:25 UTCEPSS rescore
  6. 2026-07-06 16:25 UTCEPSS rescore
  7. 2026-07-06 02:21 UTCEPSS rescore
  8. 2026-07-06 02:21 UTCEPSS rescore
  9. 2026-07-05 02:28 UTCEPSS rescore
  10. 2026-07-04 06:29 UTCEPSS rescore
  11. 2026-07-04 06:29 UTCEPSS rescore
  12. 2026-07-02 16:57 UTCEPSS rescore
  13. 2026-07-01 15:03 UTCEPSS rescore
  14. 2026-06-30 23:20 UTCEPSS rescore
  15. 2026-06-30 23:20 UTCEPSS rescore
  16. 2026-06-29 14:04 UTCEPSS rescore
  17. 2026-06-28 14:05 UTCEPSS rescore
  18. 2026-06-28 04:54 UTCEPSS rescore
  19. 2026-06-28 04:54 UTCEPSS rescore
  20. 2026-06-27 03:06 UTCEPSS rescore
  21. 2026-06-27 03:06 UTCEPSS rescore
  22. 2026-06-25 13:48 UTCEPSS rescore
  23. 2026-06-25 13:48 UTCEPSS rescore
  24. 2026-06-24 14:03 UTCEPSS rescore
  25. 2026-06-24 14:03 UTCEPSS rescore
  26. 2026-06-24 13:02 UTCOSV refresh
  27. 2026-06-23 21:31 UTCEPSS rescore
  28. 2026-06-23 21:31 UTCEPSS rescore
  29. 2026-06-22 14:24 UTCEPSS rescore
  30. 2026-06-22 14:24 UTCEPSS rescore
  31. 2026-06-21 14:55 UTCEPSS rescore
  32. 2026-06-21 14:54 UTCEPSS rescore
  33. 2026-06-21 01:58 UTCEPSS rescore
  34. 2026-06-21 01:58 UTCEPSS rescore
  35. 2026-06-19 19:24 UTCEPSS rescore
  36. 2026-06-19 19:24 UTCEPSS rescore
  37. 2026-06-18 17:51 UTCEPSS rescore
  38. 2026-06-18 17:51 UTCEPSS rescore
  39. 2026-06-17 17:51 UTCEPSS rescore
  40. 2026-06-16 17:51 UTCEPSS rescore
  41. 2026-06-15 17:46 UTCEPSS rescore
  42. 2026-06-14 23:15 UTCEPSS rescore
  43. 2026-06-13 22:58 UTCEPSS rescore
  44. 2026-06-13 22:58 UTCEPSS rescore
  45. 2026-06-12 23:10 UTCEPSS rescore
  46. 2026-06-11 13:58 UTCEPSS rescore
  47. 2026-06-10 22:16 UTCEPSS rescore
  48. 2026-06-10 13:20 UTCEPSS rescore
  49. 2026-06-08 14:15 UTCEPSS rescore
  50. 2026-06-07 17:46 UTCOSV refresh
  51. 2026-06-07 15:23 UTCEPSS rescore
  52. 2026-06-07 15:23 UTCEPSS rescore
  53. 2026-06-06 13:46 UTCEPSS rescore
  54. 2026-06-06 13:46 UTCEPSS rescore
  55. 2026-06-06 13:46 UTCEPSS rescore
  56. 2026-06-05 22:45 UTCEPSS rescore
  57. 2026-06-05 22:45 UTCEPSS rescore
  58. 2026-06-05 06:09 UTCEPSS rescore
  59. 2026-06-05 06:09 UTCEPSS rescore
  60. 2026-06-04 13:10 UTCEPSS rescore
  61. 2026-06-04 13:10 UTCEPSS rescore
  62. 2026-06-02 20:11 UTCEPSS rescore
  63. 2026-06-02 20:11 UTCEPSS rescore
  64. 2026-06-02 20:11 UTCEPSS rescore
  65. 2026-06-01 13:50 UTCEPSS rescore
  66. 2026-06-01 13:50 UTCEPSS rescore
  67. 2026-05-31 22:29 UTCEPSS rescore
  68. 2026-05-31 22:29 UTCEPSS rescore
  69. 2026-05-31 00:15 UTCEPSS rescore
  70. 2026-05-29 13:42 UTCEPSS rescore
  71. 2026-05-28 13:43 UTCEPSS rescore
  72. 2026-05-28 13:43 UTCEPSS rescore
  73. 2026-05-27 13:39 UTCEPSS rescore
  74. 2026-05-27 13:39 UTCEPSS rescore
  75. 2026-05-26 13:42 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-29437?
CVE-2021-29437 is a high vulnerability published on April 13, 2021. ScratchOAuth2 is an Oauth implementation for Scratch. Any ScratchOAuth2-related data normally accessible and modifiable by a user can be read and modified by a third party. 1. Scratch user visits 3rd party site. 2. 3rd party site asks user for Scratch username. 3. 3rd party site pretends to be user…
When was CVE-2021-29437 disclosed?
CVE-2021-29437 was first published in the National Vulnerability Database on April 13, 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-2021-29437 actively exploited?
CVE-2021-29437 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 53.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-29437?
CVE-2021-29437 has a CVSS v3 base score of 8.0 (NVD).
How do I remediate CVE-2021-29437?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-29437, 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-2021-29437

Explore →

Is Your Infrastructure Affected by CVE-2021-29437?

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

Start Free Scan →Browse All CVEs