CVE-2021-35963

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 2.4% (84th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2021-22596 (ENISA EUVD) · GHSA-88p5-c2jc-45fr (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

Update Orca HCM to version 10.9 (from the CVE record's solution, TWCERT/CC) — apply it.

The specific parameter of upload function of the Orca HCM digital learning platform does not filter file format, which allows remote unauthenticated attackers to upload files containing malicious script to execute RCE attacks.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
45
EG Risk 45/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation2.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: Update Orca HCM to version 10.9 (from the CVE record's solution, TWCERT/CC). Apply it within your standard update timelines.
EPSS PROB
2.4%
EPSS %ILE
84th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
2.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-03). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

Update Orca HCM to version 10.9 (from the CVE record's solution, TWCERT/CC). Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 19, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Oct 3, 2026
Fix named in the CVE record's solution (TWCERT/CC). Sources: cert.
CERT

一宇數位科技 Orca HCM - Unrestricted Upload of File with Dangerous Type-TWCERT/CC台灣電腦網路危機處理暨協調中心|企業資安通報協處|資安情資分享|漏洞通報|資安聯盟|資安電子報

https://www.twcert.org.tw/tw/cp-132-4923-d68e6-1.html
Web page

CHT Security Red Team Discovered Several Vulnerabilities in Well-Known Domestic Learning System|中華資安國際 CHT Security Co., Ltd.

https://www.chtsecurity.com/news/ba7b3ae7-14f3-4970-b3f6-4d97d8c7ea25

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 80× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 256 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 157 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-04 16:29 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  2. 2026-11-04 14:34 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  3. 2026-11-03 16:39 UTCEG score recompute
  4. 2026-11-03 16:39 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  5. 2026-11-03 16:38 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  6. 2026-11-02 18:32 UTCEG score recompute
  7. 2026-11-02 18:32 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  8. 2026-11-02 16:37 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  9. 2026-11-01 20:36 UTCEG score recompute
  10. 2026-11-01 20:36 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  11. 2026-11-01 16:29 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  12. 2026-10-31 22:41 UTCEG score recompute
  13. 2026-10-31 22:41 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  14. 2026-10-31 16:28 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  15. 2026-10-31 00:46 UTCEG score recompute
  16. 2026-10-31 00:46 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  17. 2026-10-30 16:30 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  18. 2026-10-30 02:51 UTCEG score recompute
  19. 2026-10-30 02:51 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  20. 2026-10-29 16:29 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  21. 2026-10-29 04:56 UTCEG score recompute
  22. 2026-10-29 04:56 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  23. 2026-10-28 16:28 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  24. 2026-10-28 07:01 UTCEG score recompute
  25. 2026-10-28 07:01 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
Show 74 more
  1. 2026-10-27 16:28 UTCEPSS rescoreEPSS 2.4% · 84th percentile
  2. 2026-10-27 09:06 UTCEG score recompute
  3. 2026-10-27 09:06 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  4. 2026-10-26 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  5. 2026-10-26 10:12 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  6. 2026-10-25 18:25 UTCEG score recompute
  7. 2026-10-25 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  8. 2026-10-25 12:17 UTCEG score recompute
  9. 2026-10-25 12:17 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  10. 2026-10-24 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  11. 2026-10-24 14:16 UTCEG score recompute
  12. 2026-10-24 14:16 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  13. 2026-10-23 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  14. 2026-10-23 16:21 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  15. 2026-10-22 18:04 UTCEG score recompute
  16. 2026-10-22 18:04 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  17. 2026-10-22 16:29 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  18. 2026-10-21 19:40 UTCEG score recompute
  19. 2026-10-21 19:40 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  20. 2026-10-21 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  21. 2026-10-20 21:44 UTCEG score recompute
  22. 2026-10-20 21:43 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  23. 2026-10-20 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  24. 2026-10-19 23:48 UTCEG score recompute
  25. 2026-10-19 23:48 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  26. 2026-10-19 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  27. 2026-10-18 23:12 UTCEG score recompute
  28. 2026-10-18 23:12 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  29. 2026-10-18 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  30. 2026-10-18 08:58 UTCEG score recompute
  31. 2026-10-18 01:15 UTCEG score recompute
  32. 2026-10-18 01:15 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  33. 2026-10-17 16:29 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  34. 2026-10-17 02:34 UTCEG score recompute
  35. 2026-10-17 02:34 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  36. 2026-10-16 16:33 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  37. 2026-10-16 04:25 UTCEG score recompute
  38. 2026-10-16 04:24 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  39. 2026-10-15 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  40. 2026-10-15 02:24 UTCEG score recompute
  41. 2026-10-15 02:24 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  42. 2026-10-14 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  43. 2026-10-13 23:06 UTCEG score recompute
  44. 2026-10-13 23:05 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  45. 2026-10-13 16:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  46. 2026-10-12 19:14 UTCGHSA enrichmentGHSA-88p5-c2jc-45fr · GitHub severity CRITICAL
  47. 2026-10-12 19:14 UTCEG score recompute
  48. 2026-10-12 16:29 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  49. 2026-10-11 23:39 UTCEG score recompute
  50. 2026-10-11 13:43 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  51. 2026-10-10 19:56 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  52. 2026-10-09 20:04 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  53. 2026-10-08 16:39 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  54. 2026-10-07 23:44 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  55. 2026-10-06 15:14 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  56. 2026-10-05 17:40 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  57. 2026-10-04 23:19 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  58. 2026-10-03 14:22 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  59. 2026-10-01 19:46 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  60. 2026-09-30 15:38 UTCEG score recompute
  61. 2026-09-30 15:00 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  62. 2026-09-29 15:15 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  63. 2026-09-28 13:47 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  64. 2026-09-27 13:41 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  65. 2026-09-26 15:54 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  66. 2026-09-26 00:21 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  67. 2026-09-24 14:00 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  68. 2026-09-23 13:44 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  69. 2026-09-22 14:44 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  70. 2026-09-21 20:28 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  71. 2026-09-20 20:12 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  72. 2026-09-19 15:38 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  73. 2026-09-18 19:23 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  74. 2026-09-17 19:23 UTCEPSS rescoreEPSS 2.4% · 83rd percentile

Frequently asked(5)

What is CVE-2021-35963?
CVE-2021-35963 is a critical-severity vulnerability; its CVE record was published on July 19, 2021. The specific parameter of upload function of the Orca HCM digital learning platform does not filter file format, which allows remote unauthenticated attackers to upload files containing malicious script to execute RCE attacks.
When was CVE-2021-35963 made public?
CVE-2021-35963 was made public on July 19, 2021: that is the date its CVE record's CNA, TWCERT/CC, gives for when the vulnerability was made public. The CVE record itself was published on July 19, 2021. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2021-35963 actively exploited?
CVE-2021-35963 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.4% probability of exploitation in the next 30 days (84th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-35963?
CVE-2021-35963 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-35963?
The CVE record's solution for CVE-2021-35963, written by its CNA TWCERT/CC, names the fix: "Update Orca HCM to version 10.9".

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-35963

Explore →

Is Your Infrastructure Affected by CVE-2021-35963?

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