smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other…
Priority CRITICAL 100Exploited in the wildCWE-755Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-78.
Summary
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.
Why it matters now
Exploitation Active In CISA KEV since 2022-03-25CISA due date 2022-04-15
EPSS 0.98972 99th percentileScored 2026-11-07
Public exploit Yes 6 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Active
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openbsd:opensmtpd:6.6:*:*:*:*:*:*:* | 6.6 | Vulnerable | OpenBSD |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* | 19.10 | Vulnerable | Canonical |
- cpe:2.3:a:openbsd:opensmtpd:6.6:*:*:*:*:*:*:* Versions 6.6 Vulnerable ·OpenBSD
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* Versions 19.10 Vulnerable ·Canonical
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2022-03-25 Added to CISA KEV
- 2026-10-02 Threatist record created from CVE-2020-7247
- 2026-10-03 Alias added: GHSA-rcw6-69h3-89fh
References
Exploit 6
- http://www.openwall.com/lists/oss-security/2020/01/28/3
- http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Escalation-Code-Execution.html
- http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Execution.html
- 20200131 LPE and RCE in OpenSMTPD (CVE-2020-7247)
- http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege-Escalation.html
Patch 2
More OpenBSD Opensmtpd vulnerabilities
- TI-2015-06389 Use-after-free vulnerability in OpenSMTPD before 5.7.2 allows remote attackers to cause a… CVSS 3.0CRITICAL 9.8
- TI-2013-01894 OpenSMTPD before 5.3.2 does not properly handle SSL sessions, which allows remote… CVSS 2.0MEDIUM 5.0
Sources
- CVE-2020-7247 · CVE Program
- CVE-2020-7247 · NVD
- CISA Known Exploited Vulnerabilities
- FIRST EPSS
- GHSA-rcw6-69h3-89fh · GitHub Advisory Database · CC BY 4.0
- CVE-2020-7247 · Red Hat security data · CC BY 4.0
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