vciy

CVE-2021-27876

INDEX BUILT · 2026-09-20

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An issue was discovered in Veritas Backup Exec before 21.2

CVE-2021-278763 of 4 sources documented this
68

rank 68 = 40 + 20 + 0 + 2 + 6

rank@v1 · this cycle

Someone is already using it

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

EPSS 0.13518 · CISA KEV listed  ·  without this subject the record ranks 28

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 8.1, from NVD  ·  without this subject the record ranks 48

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 68

How much of the world it touches

NVD CPE configurations

1 product in the CPE ranges  ·  without this subject the record ranks 66

Someone else already set the date

CISA KEV remediation due date

CISA remediation date held  ·  without this subject the record ranks 62

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$595,000over the next 30 days, if this record is yours
Movement-$1.84Mon 2025-11-21, the last material move, 9 months before this reading
Basisassumeda published average, not your estate

$595,000 = $4.99M incident cost x 0.8814887365328109 exposure x 0.13518 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

0.13518EPSSKEV · LISTED
Severity8.1 HIGHreceipt
Harmpartial impact · ransomware-linkedreceipt
Exploitationransomware use knownreceipt
Defenseunaffected versions publishedreceipt
Movementrisenreceipt
PLATEAU10Minimal movement since 2026-06-15, 81 days at 0.14, as of 2026-09-04. arc-rules@v1

Foresight · where to check next

No weakness class or product neighbourhood is held for this record, so this index cannot name anywhere to check next. That is an absence in the record, not a finding about the software.

Color is a claim, not decoration:the hostile worldthe defenseno signal

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Reachnetwork-reachable · low privileges required · no user interaction · low attack complexityreceipt
ImpactComplete confidentiality and integrity lossreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classNo CWE mapping in held sources.
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 branchbackup exec 21.2receipt
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 2023-04-28receipt
CISA required actionApply updates per vendor instructions.receipt
Published to CISA KEV767 daysderived

Exploit Status & Known PoCs a ladder, not a score

Current rung: Ransomware campaign use known, 2023-04-07.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 1 public repository2026-06-18receipt
  • RUNG 3Exploited in the wild · CISA KEV listed2023-04-07receipt
  • RUNG 4Ransomware campaign use known2023-04-07receipt

Authority who says so

CVSS, the CNA8.1 HIGHreceipt
CVSS, NVD8.1 HIGHreceipt
Exploit probability0.13518 · top 4% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned bymitrereceipt
Recorded changes60 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Named in the CPE rangesVeritas backup execreceipt
Published rangesveritas backup exec < 21.2receipt

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

An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is typically completed over a secure TLS communication. However, due to a vulnerability in the SHA Authentication scheme, an attacker is able to gain unauthorized access and complete the authentication process. Subsequently, the client can execute data management protocol commands on the authenticated connection. By using crafted input parameters in one of these commands, an attacker can access an arbitrary file on the system using System privileges. receipt

NVD's analysis a second authority

severity
8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
affected versions
veritas backup exec < 21.2
also scored by
[email protected] 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

check it yourself veritas.com packetstormsecurity.com receipt

Dated events

2022-02-04EPSS moved 0.02 to 0.092023-04-07Added to CISA KEV2023-04-08EPSS moved 0.00 to 0.812023-04-28CISA remediation due2026-06-15EPSS moved 0.01 to 0.13

Movement the material steps

14 Apr 20210.00416
7 Mar 20238.8e-4 · scoring model v2023.03.01
8 Apr 20230.80513 · crossed 0.10 and 0.50
3 Jul 20230.67099
10 Sep 20230.77910
8 Mar 20250.34587 · crossed 0.50
17 Mar 20250.0064 · crossed 0.10 · scoring model v2025.03.14
18 Nov 20250.44977 · crossed 0.10
21 Nov 20250.03222 · crossed 0.10
15 Jun 20260.13173 · crossed 0.10 · scoring model v2026.06.15
12 Aug 20260.13518
Show all 46 observations
14 Apr 20210.00416
6 Jan 20220.0184
4 Feb 20220.09029
1 Apr 20220.00885
7 Mar 20238.8e-4
8 Mar 20230.00088
8 Apr 20230.80513
11 Apr 20230.79280
8 May 20230.77611
5 Jun 20230.72762
3 Jul 20230.67099
8 Jul 20230.65488
1 Aug 20230.69492
14 Aug 20230.71338
10 Sep 20230.77910
20 Oct 20230.74332
29 Nov 20230.72580
11 Dec 20230.69769
26 Dec 20230.74680
22 Jan 20240.74455
4 Mar 20240.72725
18 Mar 20240.73335
4 Jul 20240.74314
17 Dec 20240.87774
3 Jan 20250.85831
22 Feb 20250.87362
8 Mar 20250.34587
17 Mar 20250.0064
29 Mar 20250.02142
30 Mar 20250.0064
17 Sep 20250.00722
22 Oct 20250.00862
1 Nov 20250.01725
12 Nov 20250.0278
18 Nov 20250.44977
21 Nov 20250.03222
29 Nov 20250.01972
19 Feb 20260.00987
11 Apr 20260.01072
12 Apr 20260.00986
20 Apr 20260.00847
2 May 20260.01057
22 May 20260.00908
15 Jun 20260.13173
23 Jun 20260.13411
12 Aug 20260.13518

46 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 0.13518Published2021-03-01CISA KEV2023-04-07Public PoC2026-06-18Index as of2026-09-04

Listed by CISA 767 days after it published and the record had been public for 5 years, 6 months when this index was last written.

No material movement in 23 days as of the last ingest this index recorded.

Published 2021-03-01 receipt · CISA KEV 2023-04-07 receipt · Public PoC 2026-06-18 receipt · Index as of 2026-09-04 derived

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