CASCACascade Atlas

Evidence dossier

CVE-2020-7247

smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP…

Exploited in the wild (CISA KEV since Mar 25, 2022). NVD reports CVSS 3.1 9.8. EPSS estimates 99.0% exploit likelihood as of Oct 22, 2026.

90.5–91.2Priority evidence range
Evidence through Oct 22, 2026, 6:07 PM UTC

As of Oct 22, 2026

Normalized restatement

smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.

State
PUBLISHED
Published
Jan 29, 2020
Updated
Oct 21, 2025
Evidence coverage
97%

Evidence chronology

What was known when

Download this view's receipt →
  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
    mitre

    Record text: smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.

    Inspect raw assertion
    Field
    container
    Value
    smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: OpenSMTPD Remote Code Execution Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    OpenSMTPD Remote Code Execution Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 98.97% probability · 99.93th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.989720000000; percentile 0.999310000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 25, 2022 · first observed Sep 1, 2026

Exploit likelihood98.97%

FIRST EPSS · score date Oct 22, 2026 · 99.9th percentile · first observed Oct 22, 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 statusLast verified source snapshot retained

The last verified source boundary remains in force for this claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
Review source contract
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Oct 22, 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
Oct 22, 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 ↗
mitreOriginal assertion
Record text

smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.

Inspect raw assertion
Field
container
Value
smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

OpenSMTPD Remote Code Execution Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
OpenSMTPD Remote Code Execution Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

98.97% probability · 99.93th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.989720000000; percentile 0.999310000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
6Underlying assertions
4Canonical products
6Target assertions
0Constraint assertions

Grouped from 4 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

5 scope groups

mitre · source assertedn/an/aDirect source scope
Affected: n/a
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "n/a"}]
NVD CPE · OPERATING SYSTEMcanonicalubuntu_linuxVulnerable target · 2 assertions
Version 18.04; Version 19.10Canonical identity product-a18840e4673d48e569064752e9575849e99b3f173c63d7c965c4c193bcaebef2Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    23a7c53f-b80f-4e6a-afa9-58eea84be11d
  2. cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a31c8344-3e02-4eb8-8bd8-4c84b7959624
NVD CPE · OPERATING SYSTEMdebiandebian_linuxVulnerable target · 2 assertions
Version 10.0; Version 9.0Canonical identity product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447eLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    07b237a9-69a3-4a9c-9da0-4e06bd37ae73
  2. cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    deece5fc-cacf-4496-a3e7-164736409252
NVD CPE · OPERATING SYSTEMfedoraprojectfedoraVulnerable target · 1 assertions
Version 32Canonical identity product-c96c7662a6606ed7594747da3d7ba9ee3a9758ab11658f6a3f42616361472e47Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    36d96259-24bd-44e2-96d9-78ce1d41f956
NVD CPE · APPLICATIONopenbsdopensmtpdVulnerable target · 1 assertions
Version 6.6Canonical identity product-7fbc7a93cbdf6667afcdd57dd171987ee0881b67e18d146c8416442511d65e1dLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:openbsd:opensmtpd:6.6:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    e2d1d6e5-21ba-40cc-870f-a940dd814532

Affected-product evidence

Accepted scope and product mapping

4 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-66ae8c5e06427f7450637d18322b0dc411c0b469d940341cf076a620d444fe3c · product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447e

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
c50b1414-7180-41e3-90e0-577872bb09e6c92775f3-a45c-4557-bfc4-782707a58ed1
Mapping establishedEvidence supported

vendor-1275f7a3702cf8c2ab5a02230416e6e2ee90ea9f58240f21630da8504266114e · product-7fbc7a93cbdf6667afcdd57dd171987ee0881b67e18d146c8416442511d65e1d

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
493d656b-e7ed-4103-a269-638200765a1f
Mapping establishedEvidence supported

vendor-c57a6167e95991f72f9616ac32b40463ac13c5f4929fcce3efc058b09a445b54 · product-a18840e4673d48e569064752e9575849e99b3f173c63d7c965c4c193bcaebef2

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
1c5f7764-7df1-4fbb-a20f-ca29b02688a29a4937c8-4683-4976-9fcc-f5282fce49f9
Mapping establishedEvidence supported

vendor-2d566b06907460b10e6e48c8544126e19f1d6df137983056edae8d0b51e34e45 · product-c96c7662a6606ed7594747da3d7ba9ee3a9758ab11658f6a3f42616361472e47

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
1fac8e99-bdcf-4689-ac8e-4d687dc6e471
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
Oct 22, 2026
Retained assertion IDs
700088d8-9129-46cf-a4af-6487173066e5

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
10.0
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:C/I:C/A:C
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.