vciy

CVE-2021-40539

INDEX BUILT · 2026-09-20

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Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution.

CVE-2021-405393 of 4 sources documented this
75

rank 75 = 40 + 25 + 0 + 4 + 6

rank@v1 · act now

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.98960 · CISA KEV listed  ·  without this subject the record ranks 35

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 9.8, from NVD  ·  without this subject the record ranks 50

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 75

How much of the world it touches

NVD CPE configurations

2 products in the CPE ranges  ·  without this subject the record ranks 71

Someone else already set the date

CISA KEV remediation due date

CISA remediation date held  ·  without this subject the record ranks 69

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$4.94Mover the next 30 days, if this record is yours
Movement+$2.87Mon 2022-02-04, the last material move, 4 years, 7 months before this reading
Basisassumeda published average, not your estate

$4.94M = $4.99M incident cost x 1 exposure x 0.9896 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.9896EPSSKEV · LISTED
Severity9.8 CRITICALreceipt
Harmtotal loss · unauthenticated · ransomware-linkedreceipt
Exploitationransomware use knownreceipt
Defenseunaffected versions publishedreceipt
Movementscoring model changedreceipt
PLATEAU10Minimal movement since 2022-02-04, 1673 days at 0.99, as of 2026-09-04. arc-rules@v1

Foresight · where to check next

Apache TomcatCVE-2020-1550540539

This record is one instance of CWE-706, use of incorrectly-resolved name or reference. The index holds 137 prior instances of this class, 2 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signalspoke length is how much of the record matches, not how bad it is

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Harm, if it fires from the vector and the weakness

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Reachnetwork-reachable · no privileges required · no user interaction · low attack complexityreceipt
ImpactComplete confidentiality, integrity and availability lossreceipt
Scored fromCVSS v3.1 · NVD's vectorreceipt
Weakness classCWE-706 Use of Incorrectly-Resolved Name or Referencereceipt
Published consequencesCWE-706: Confidentiality, Integrity: Read Application Data, Modify Application Data[email protected]
Ransomware campaign useKnown (CISA)receipt

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

First unaffected version, by branchmanageengine adselfservice plus 6.1receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.
CISA remediation statusoverdue since 2021-11-17receipt
CISA required actionApply updates per vendor instructions.receipt
Published to CISA KEV57 daysderived

Exploit Status & Known PoCs a ladder, not a score

Current rung: Ransomware campaign use known, 2021-11-03.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 5 public repositories2021-09-17receipt
  • RUNG 3Exploited in the wild · CISA KEV listed2021-11-03receipt
  • RUNG 4Ransomware campaign use known2021-11-03receipt

Authority who says so

CVSS, NVD9.8 CRITICALreceipt
Exploit probability0.9896 · top 0.07% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned bymitrereceipt
Recorded changes57 · last 17 Sep 2026derived

Affected & Fixed Versions as published

Named in the CPE rangesZohocorp manageengine adselfservice plusreceipt
Published rangeszohocorp manageengine adselfservice plus < 6.1; zohocorp manageengine adselfservice plus 6.1receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution. receipt

NVD's analysis a second authority

severity
9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
weakness
CWE-706
affected versions
zohocorp manageengine adselfservice plus < 6.1; zohocorp manageengine adselfservice plus 6.1
also scored by
9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

check it yourself manageengine.com manageengine.com packetstormsecurity.com receipt

Dated events

2021-11-03Added to CISA KEV2021-11-17CISA remediation due2021-11-25EPSS moved 0.06 to 0.322021-11-27EPSS moved 0.32 to 0.382022-02-04EPSS moved 0.38 to 0.96

Movement the material steps

8 Sep 20210.01374
25 Nov 20210.31602 · crossed 0.10
4 Feb 20220.95627 · crossed 0.50 and 0.90
7 Mar 20230.97526 · scoring model v2023.03.01
17 Mar 20250.94424 · scoring model v2025.03.14
15 Jun 20260.9896 · scoring model v2026.06.15
Show all 43 observations
8 Sep 20210.01374
17 Sep 20210.05885
25 Nov 20210.31602
27 Nov 20210.3817
4 Feb 20220.95627
29 Jul 20220.95954
7 Mar 20230.97526
31 Mar 20230.97523
15 Apr 20230.97524
29 Apr 20230.97508
8 May 20230.97519
12 Jun 20230.97497
27 Jun 20230.97498
8 Jul 20230.97465
11 Jul 20230.97438
15 Jul 20230.97472
23 Aug 20230.97487
4 Sep 20230.97492
21 Sep 20230.97511
22 Sep 20230.97422
4 Oct 20230.97410
18 Oct 20230.97402
30 Nov 20230.97412
7 Feb 20240.97492
5 Mar 20240.97499
13 Apr 20240.97501
27 Apr 20240.97504
23 May 20240.97492
13 Aug 20240.97477
26 Aug 20240.97474
24 Sep 20240.97467
24 Oct 20240.97469
24 Nov 20240.97496
17 Dec 20240.97433
24 Dec 20240.97462
10 Jan 20250.97477
25 Jan 20250.97449
10 Feb 20250.97479
17 Mar 20250.94424
18 Nov 20250.94284
21 Nov 20250.94424
7 Jun 20260.94412
15 Jun 20260.9896

43 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.9896Published2021-09-07Public PoC2021-09-17CISA KEV2021-11-03Index as of2026-09-04

Listed by CISA 57 days after it published and the record had been public for 4 years, 11 months when this index was last written.

No material movement in 81 days as of the last ingest this index recorded.

Published 2021-09-07 receipt · Public PoC 2021-09-17 receipt · CISA KEV 2021-11-03 receipt · Index as of 2026-09-04 derived

The pattern, elsewhere

This record is one instance of CWE-706, use of incorrectly-resolved name or reference. The index holds 137 prior instances of this class, 2 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2025-24813 · Apache Tomcatmatches 8 of 8KEV listed · 2025receipt
CVE-2020-15505matches 8 of 8KEV listed · 2020receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

137 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

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