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ExploitedIn CISA KEVFix available

CVE-2020-7247

Exploitation confirmed. First attested on 2022-03-25 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2020-01-29
  • WeaknessCWE-755 · CWE-78

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2020-01-2916:15CVE publishedNVD
  2. 2020-01-30Exploit-DB entryExploit-DB
  3. 2022-03-25Added to the CISA KEV catalogCISA KEV
  4. 2022-03-25Listed as exploited by GCVEGCVE
  5. 2022-03-25Exploitation first reportedCISA KEV
  6. 2025-02-0420:20SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-7247?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-7247?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Canonical ubuntu linux
BranchAffectedFixed in
18.4= 18.04no fix published
19.10= 19.10no fix published
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published
10.0= 10.0no fix published
Fedoraproject fedora
BranchAffectedFixed in
32.x= 32no fix published

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • opensmtpdUbuntu:Pro:16.04:LTSall versions · fixed in 5.7.3p2-1ubuntu0.1~esm1
  • opensmtpdUbuntu:Pro:16.04:LTSall versions · fixed in 5.7.3p2-1ubuntu0.1~esm2
  • opensmtpdUbuntu:Pro:14.04:LTSall versions · fixed in 5.4.1p1-1ubuntu0.1~esm1
  • opensmtpdUbuntu:18.04:LTSall versions · fixed in 6.0.3p1-1ubuntu0.1
  • opensmtpdDebian:14all versions · fixed in 6.6.2p1-1
  • opensmtpdDebian:13all versions · fixed in 6.6.2p1-1
  • opensmtpdDebian:12all versions · fixed in 6.6.2p1-1
  • opensmtpdDebian:10all versions · fixed in 6.0.3p1-5+deb10u3

16 more package ranges on OSV.dev

Vendor advisories

  • CVE-2020-7247 Red Hat Product Security

    opensmtpd: arbitrary commands execution in smtp_mailaddr in smtp_session.c via crafted SMTP session

Full record on NVD

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-04-15

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
EDB-47984EDB-48038EDB-48051
Exploit-DB
Proof-of-concept repositories
11 repositories, unverifiedFiroSolutions/cve-2020-7247-exploitsuperzerosec/cve-2020-7247r0lh/CVE-2020-7247QTranspose/CVE-2020-7247-exploitbytescrappers/CVE-2020-7247
PoC-in-GitHub
Metasploit modules
1 moduleexploit/unix/smtp/opensmtpd_mail_from_rcerank: excellentModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2022-03-25
Patch Due Date
2022-04-15
Ransomware Use
Unknown
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2020-01-29
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-rcw6-69h3-89fh

Frequently asked questions

What is 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 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.

Is CVE-2020-7247 actively exploited?

Yes. CVE-2020-7247 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-04-15.

What is the CVSS score for CVE-2020-7247?

CVE-2020-7247 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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