CASCACascade Atlas

Evidence dossier

CVE-2020-5135

A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to…

Exploited in the wild (CISA KEV since Mar 15, 2022). NVD reports CVSS 3.1 9.8. EPSS estimates 26.9% exploit likelihood as of Aug 27, 2026.

78.4–79.7Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

State
PUBLISHED
Published
Oct 12, 2020
Updated
Oct 21, 2025
Evidence coverage
97%

Evidence chronology

What was known when

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  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    sonicwall

    Record text: A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

    Inspect raw assertion
    Field
    container
    Value
    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: SonicWall SonicOS Buffer Overflow Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    SonicWall SonicOS Buffer Overflow Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 26.87% probability · 97.88th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.268690000000; percentile 0.978830000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 15, 2022 · first observed Jul 19, 2026

Exploit likelihood26.87%

FIRST EPSS · score date Aug 27, 2026 · 97.9th percentile · first observed Aug 27, 2026

SeverityCVSS 9.8

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
sonicwallOriginal assertion
Record text

A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

Inspect raw assertion
Field
container
Value
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

SonicWall SonicOS Buffer Overflow Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
SonicWall SonicOS Buffer Overflow Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

26.87% probability · 97.88th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.268690000000; percentile 0.978830000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
5Underlying assertions
2Canonical products
5Target assertions
0Constraint assertions

Grouped from 1 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

3 scope groups

sonicwall · source assertedSonicWallSonicOSDirect source scope
Affected: SonicOS 6.5.4.7-79n and earlierAffected: SonicOS 6.5.1.11-4n and earlierAffected: SonicOS 6.0.5.3-93o and earlierAffected: SonicOSv 6.5.4.4-44v-21-794 and earlierAffected: SonicOS 7.0.0.0-1
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "SonicOS 6.5.4.7-79n and earlier"}, {"status": "affected", "version": "SonicOS 6.5.1.11-4n and earlier"}, {"status": "affected", "version": "SonicOS 6.0.5.3-93o and earlier"}, {"status": "affected", "version": "SonicOSv 6.5.4.4-44v-21-794 and earlier"}, {"status": "affected", "version": "SonicOS 7.0.0.0-1"}]
NVD CPE · OPERATING SYSTEMsonicwallsonicosVulnerable target · 4 assertions
Any version (unconstrained) (<= 6.0.5.3); Any version (unconstrained) (>= 6.5.0.0, <= 6.5.1.11); Any version (unconstrained) (>= 6.5.4.0, <= 6.5.4.7); Version 7.0.0.0Canonical identity product-85898d6fe491d9f6f381bbdf2d6cef63a8d780eebbf13fe9fb76aeb30af6b3d7Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 6.5.0.0; through including 6.5.1.11
    Match ID
    08df961e-08dd-47ec-9ab1-3a3ff79e1f7a
  2. cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    from including 6.5.4.0; through including 6.5.4.7
    Match ID
    8302038f-fa49-4cf2-b064-3ee1103b99f1
  3. cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through including 6.0.5.3
    Match ID
    3937590e-0915-4fa8-ae69-a5197a839931
  4. cpe:2.3:o:sonicwall:sonicos:7.0.0.0:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    05c0300f-44ab-482c-ba6d-b9f2ed77037a
NVD CPE · OPERATING SYSTEMsonicwallsonicosvVulnerable target · 1 assertions
Any version (unconstrained) (<= 6.5.4.4)Canonical identity product-96bfe7175ee31c8fb04fcdd86f7c23de908be0d19b2813f9d26c4b1bbe830152Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:sonicwall:sonicosv:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    through including 6.5.4.4
    Match ID
    8bbb86a1-803b-4b76-bf3d-4a9bcc5ad302

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-85898d6fe491d9f6f381bbdf2d6cef63a8d780eebbf13fe9fb76aeb30af6b3d7

Source class
Nvd cpe vulnerable target
Assertions
4
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
97ae90d3-fabc-4bf2-a99c-f0a2a7d773eeaabe1847-8cef-4e73-bcd3-e317fc2edd86d2561531-2e85-4e1a-920f-707d82238118faf5e51d-fda7-4588-86b7-ad2022c96e4d
Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-96bfe7175ee31c8fb04fcdd86f7c23de908be0d19b2813f9d26c4b1bbe830152

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
b5ad6353-ab83-4d6d-bfa6-8856fc2f60fa
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
7e3bae4d-6555-4a8f-ba88-155b4638ff7f

Assessments

CVSS by origin

9.8
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

9.8Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
9.8
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.