vciy

CVE-2021-27877

INDEX BUILT · 2026-09-20

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An issue was discovered in Veritas Backup Exec before 21.2

CVE-2021-278773 of 4 sources documented this
77

rank 77 = 40 + 25 + 4 + 2 + 6

rank@v1 · act now

Someone is already using it

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

EPSS 0.64910 · CISA KEV listed  ·  without this subject the record ranks 37

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 52

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

rose on 2025-10-23  ·  without this subject the record ranks 73

How much of the world it touches

NVD CPE configurations

1 product in the CPE ranges  ·  without this subject the record ranks 75

Someone else already set the date

CISA KEV remediation due date

CISA remediation date held  ·  without this subject the record ranks 71

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$2.33Mover the next 30 days, if this record is yours
Movement-$1.75Mon 2025-11-21, the last material move, 9 months before this reading
Basisassumeda published average, not your estate

$2.33M = $4.99M incident cost x 0.7179585840212677 exposure x 0.6491 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

0.6491EPSSKEV · LISTED
Severity8.2 HIGHreceipt
Harmunauthenticated · network · ransomware-linkedreceipt
Exploitationransomware use knownreceipt
Defenseunaffected versions publishedreceipt
Movementthreshold crossedreceipt
RISING10Risen from 0.00416 to 0.6491 across 55 observations. 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

Sources disagree here.

Severity score
Mitre8.2 HIGHreceipt
NVD9.8 CRITICALreceipt
What it costs
MitreComplete confidentiality loss; partial integrity lossreceipt
NVDComplete confidentiality, integrity and availability lossreceipt

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

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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 loss; partial 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 repository2026-07-02receipt
  • RUNG 3Exploited in the wild · CISA KEV listed2023-04-07receipt
  • RUNG 4Ransomware campaign use known2023-04-07receipt

Authority who says so

CVSS, the CNA8.2 HIGHreceipt
CVSS, NVD9.8 CRITICALreceipt
Exploit probability0.6491 · top 0.79% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned bymitrereceipt
Recorded changes69 · last 18 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. It supports multiple authentication schemes: SHA authentication is one of these. This authentication scheme is no longer used in current versions of the product, but hadn't yet been disabled. An attacker could remotely exploit this scheme to gain unauthorized access to an Agent and execute privileged commands. 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
affected versions
veritas backup exec < 21.2
also scored by
[email protected] 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

The CNA scored it 8.2 and NVD 9.8. Both are shown because both were published; we do not pick one.

check it yourself veritas.com packetstormsecurity.com receipt

Dated events

2022-02-04EPSS moved 0.02 to 0.092023-04-07Added to CISA KEV2023-04-28CISA remediation due2025-03-08EPSS moved 0.88 to 0.282026-06-15EPSS moved 0.40 to 0.65

Movement the material steps

14 Apr 20210.00416
7 Mar 20230.00623 · scoring model v2023.03.01
8 Apr 20230.59870 · crossed 0.10 and 0.50
5 Jun 20230.49416 · crossed 0.50
1 Aug 20230.53552 · crossed 0.50
10 Sep 20230.64994
17 Jun 20240.75295
17 Dec 20240.85462
8 Mar 20250.27949 · crossed 0.50
17 Mar 20250.00802 · crossed 0.10 · scoring model v2025.03.14
23 Oct 20250.28474 · crossed 0.10
18 Nov 20250.88334 · crossed 0.50
21 Nov 20250.39395 · crossed 0.50
16 Dec 20250.29375
21 Mar 20260.395
15 Jun 20260.6491 · crossed 0.50 · scoring model v2026.06.15

This score more than doubled inside 72 hours. Both observations are in the full history below.

Show all 55 observations
14 Apr 20210.00416
6 Jan 20220.0184
4 Feb 20220.09029
1 Apr 20220.00885
7 Mar 20230.00623
8 Apr 20230.59870
8 May 20230.58269
24 May 20230.56733
5 Jun 20230.49416
3 Jul 20230.41998
8 Jul 20230.48654
1 Aug 20230.53552
14 Aug 20230.55925
10 Sep 20230.64994
6 Oct 20230.66251
20 Oct 20230.61296
15 Nov 20230.63189
11 Dec 20230.61682
26 Dec 20230.67555
22 Jan 20240.73044
18 Mar 20240.73648
17 Jun 20240.75295
4 Jul 20240.76210
17 Dec 20240.85462
19 Dec 20240.87499
5 Feb 20250.86746
22 Feb 20250.88159
8 Mar 20250.27949
17 Mar 20250.00802
19 Mar 20250.0097
29 Mar 20250.02983
30 Mar 20250.0097
17 Sep 20250.01094
29 Sep 20250.02752
22 Oct 20250.03368
23 Oct 20250.28474
1 Nov 20250.26957
4 Nov 20250.28481
12 Nov 20250.38316
18 Nov 20250.88334
21 Nov 20250.39395
26 Nov 20250.41565
29 Nov 20250.31099
8 Dec 20250.32048
16 Dec 20250.29375
12 Mar 20260.33564
21 Mar 20260.395
3 Apr 20260.42433
4 Apr 20260.42919
9 Apr 20260.40751
11 Apr 20260.42532
12 Apr 20260.40728
26 Apr 20260.45502
6 Jun 20260.40344
15 Jun 20260.6491

55 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 0.6491Published2021-03-01CISA KEV2023-04-07Public PoC2026-07-02Index as of2026-09-04

Listed by CISA 767 days after it published, exploit probability more than doubled between 2025-10-22 and 2025-10-23 (0.03368 → 0.28474) and the record had been public for 5 years, 6 months when this index was last written.

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

Published 2021-03-01 receipt · CISA KEV 2023-04-07 receipt · Public PoC 2026-07-02 receipt · Index as of 2026-09-04 derived

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