CVE-2020-7247
RCE in Debian Linux 10.0 … 9.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2020-7247 is a critical-severity OS Command Injection (CWE-78) vulnerability in Debian Debian Linux. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique NTDS (T1003.003); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2020-7247 is a command injection vulnerability in the smtp_mailaddr function within smtp_session.c of OpenSMTPD 6.6, as deployed in OpenBSD 6.6 and related products. The flaw stems from an incorrect return value when input validation fails, enabling shell metacharacters supplied in a MAIL FROM field to be processed during a crafted SMTP session. It impacts the default configuration when the "uncommented" setup is in use and is tracked under CWE-78 and CWE-755 with a CVSS 3.1 base score of 9.8.
Remote unauthenticated attackers can exploit the issue over the network by establishing an SMTP session and injecting arbitrary commands that execute with root privileges, achieving full system compromise without requiring user interaction.
Public exploit code for remote code execution and local privilege escalation against affected OpenSMTPD versions has been published on PacketStorm, confirming the vulnerability's practical exploitability in default deployments.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2020-28374
Vulnerability Data
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…
more
the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.
- CWE(s)
- KEV Date Added
- 25 March 2022
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.2.5V1.2.8
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Provides defined handling (alert and additional actions) for the exceptional condition of audit logging failure.
Supplies a concrete handling action (safe mode) for exceptional conditions, mitigating risks from improper or absent handling that could allow continued attacks.
By preparing users for contingency scenarios, the control promotes proper handling of exceptional conditions instead of default or unsafe behaviors.
An updated contingency plan defines current actions for exceptional conditions, reducing the window for attackers to exploit improper handling leading to system failure.
Procedures ensure proper handling of exceptional conditions to support effective incident response.
Incident response testing confirms proper handling of exceptional conditions to limit exploit impact.
Gives users guidance on incident handling, reducing improper handling of exceptional conditions that could stem from exploited weaknesses.
Enforces structured response to exceptional conditions so the system cannot remain in an unsafe state.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Documented operating procedures may specify exception handling but do not guarantee implementation.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.