vciy

CVE-2021-35211

INDEX BUILT · 2026-09-20

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Serv-U Remote Memory Escape Vulnerability

CVE-2021-352114 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 0.91160 · 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 10.0, 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$4.55Mover the next 30 days, if this record is yours
Movement+$3.31Mon 2024-02-07, the last material move, 2 years, 6 months before this reading
Basisassumeda published average, not your estate

$4.55M = $4.99M incident cost x 1 exposure x 0.9116 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

0.9116EPSSKEV · LISTED
Severity9 CRITICALreceipt
Harmtotal loss · unauthenticated · ransomware-linkedreceipt
Exploitationransomware use knownreceipt
Defensefix version namedreceipt
Movementscoring model changedreceipt
PLATEAU10Minimal movement since 2024-02-07, 940 days at 0.91, as of 2026-09-04. arc-rules@v1

Foresight · where to check next

Ivanti ConnectPHPFortinetFortinet35211

This record is one instance of CWE-787, out-of-bounds write. The index holds 14892 prior instances of this class, 163 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

Sources disagree here.

Severity score
SolarWinds9 CRITICALreceipt
NVD10 CRITICALreceipt

Both shown, dated. We don't pick winners. disagreement-rules@v1

Running SolarWinds Serv-U Managed File Transfer…? Check your version

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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 · high attack complexityreceipt
ImpactComplete confidentiality, integrity and availability loss, with impact beyond the vulnerable componentreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classCWE-787 Out-of-bounds Writereceipt
Published consequencesCWE-787: Integrity: Modify Memory, Execute Unauthorized Code or Commands; Availability: DoS: Crash, Exit, or Restart; Other: Unexpected State[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.

Fixed in15.2.3 HF1receipt
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 KEV112 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 · 2 public repositories2021-09-30receipt
  • RUNG 3Exploited in the wild · CISA KEV listed2021-11-03receipt
  • RUNG 4Ransomware campaign use known2021-11-03receipt

Authority who says so

CVSS, the CNA9 CRITICALreceipt
CVSS, NVD10 CRITICALreceipt
Exploit probability0.9116 · top 0.20% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned bySolarWindsreceipt
Recorded changes81 · last 18 Sep 2026derived

Affected & Fixed Versions as published

Affected productSolarWinds Serv-U Managed File Transfer Server and Serv-U Secured FTPreceipt
Published rangessolarwinds serv-u < 15.2.3; solarwinds serv-u 15.2.3receipt
Fixed in15.2.3 HF1receipt

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

Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability. receipt

NVD's analysis a second authority

severity
10 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
weakness
CWE-787
affected versions
solarwinds serv-u < 15.2.3; solarwinds serv-u 15.2.3
also scored by
[email protected] 9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

The CNA scored it 9 and NVD 10. Both are shown because both were published; we do not pick one.

check it yourself solarwinds.com microsoft.com receipt

Dated events

2021-11-03Added to CISA KEV2021-11-17CISA remediation due2022-02-04EPSS moved 0.06 to 0.302024-02-07EPSS moved 0.28 to 0.94

Movement the material steps

15 Jul 20210.01374
4 Feb 20220.29514 · crossed 0.10
7 Mar 20230.95602 · crossed 0.50 and 0.90 · scoring model v2023.03.01
22 Sep 20230.32069 · crossed 0.50 and 0.90
7 Feb 20240.94034 · crossed 0.50 and 0.90
17 Mar 20250.94144 · scoring model v2025.03.14
15 Jun 20260.9116 · scoring model v2026.06.15
Show all 67 observations
15 Jul 20210.01374
30 Sep 20210.05885
4 Feb 20220.29514
7 Mar 20230.95602
18 Apr 20230.95357
29 Jun 20230.94597
8 Jul 20230.94619
11 Jul 20230.94391
22 Sep 20230.32069
6 Oct 20230.25940
3 Nov 20230.29085
30 Nov 20230.30450
27 Dec 20230.27637
7 Feb 20240.94034
17 Feb 20240.93838
28 Mar 20240.93668
4 Jun 20240.92104
18 Jun 20240.92302
1 Jul 20240.92705
16 Jul 20240.92234
15 Aug 20240.92739
13 Sep 20240.95058
2 Dec 20240.94868
17 Dec 20240.93005
8 Feb 20250.93458
13 Mar 20250.93614
17 Mar 20250.94144
19 Mar 20250.94139
20 Mar 20250.94144
23 Mar 20250.94139
24 Mar 20250.94144
27 Mar 20250.94139
1 May 20250.93999
4 May 20250.94139
1 Jun 20250.93999
4 Jun 20250.94139
1 Jul 20250.93999
4 Jul 20250.94139
1 Aug 20250.93999
4 Aug 20250.94139
25 Aug 20250.93999
28 Aug 20250.94139
1 Sep 20250.93999
4 Sep 20250.94139
21 Sep 20250.94108
1 Oct 20250.93959
4 Oct 20250.94108
22 Oct 20250.94171
27 Oct 20250.94162
28 Oct 20250.94393
31 Oct 20250.9436
1 Nov 20250.94287
4 Nov 20250.9436
18 Nov 20250.93937
21 Nov 20250.9436
30 Nov 20250.94393
1 Dec 20250.94331
2 Dec 20250.94271
4 Dec 20250.94347
18 Dec 20250.94321
1 Jan 20260.94237
4 Jan 20260.94321
1 Feb 20260.94237
4 Feb 20260.94321
1 Mar 20260.94237
4 Mar 20260.94321
15 Jun 20260.9116

67 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 0.9116Published2021-07-14Public PoC2021-09-30CISA KEV2021-11-03Index as of2026-09-04

Listed by CISA 112 days after it published and the record had been public for 5 years, 1 month when this index was last written.

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

Published 2021-07-14 receipt · Public PoC 2021-09-30 receipt · CISA KEV 2021-11-03 receipt · Index as of 2026-09-04 derived

The pattern, elsewhere

This record is one instance of CWE-787, out-of-bounds write. The index holds 14892 prior instances of this class, 163 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2025-0282 · Ivanti Connect Securematches 8 of 9KEV listed · 2025receipt
CVE-2025-22457 · Ivanti Connect Securematches 8 of 9KEV listed · 2025receipt
CVE-2019-11043 · PHPmatches 7 of 9KEV listed · 2019receipt
CVE-2024-21762 · Fortinet FortiProxymatches 6 of 9KEV listed · 2024receipt
CVE-2022-42475 · Fortinet FortiProxymatches 6 of 9KEV listed · 2023receipt
CVE-2023-27997 · Fortinet FortiOS-6K7Kmatches 6 of 9KEV listed · 2023receipt

"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

14892 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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