CVE-2020-8793
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux...
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
4.7
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
CVE-2020-8793- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.7 Medium
AV:L/AC:M/Au:N/C:C/I:N/A:N - Weakness
- CWE-367, CWE-426
- Updated
- 2026-11-02
CVE List No score
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
CVE-2020-8793- Updated
- 2026-11-02
EUVDEUVD-2020-29641 No score
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
EUVD-2020-29641- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-m2cf-xghm-rxmc No score
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux...
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
GHSA-m2cf-xghm-rxmc- Weakness
- CWE-426
- Updated
- 2026-11-02
OSV
4.7
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
CVE-2020-8793- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-8793
4.7
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
DEBIAN-CVE-2020-8793- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-8793
4.7
OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.
- Record
UBUNTU-CVE-2020-8793- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUSN-4294-1 No score
OpenSMTPD vulnerabilities
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)
It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An unprivileged local attacker could read the first line of any file on the filesystem. (CVE-2020-8793)
- Record
USN-4294-1- Updated
- 2026-11-02
OSVUSN-4875-1 No score
opensmtpd vulnerabilities
It was discovered that OpenSMTPD incorrectly verified the sender's or receiver's e-mail addresses under certain conditions. An attacker could possibly use this vulnerability to execute arbitrary commands as root. (CVE-2020-7247)
It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An unprivileged local attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 ESM. (CVE-2020-8793)
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could possibly use this vulnerability to execute arbitrary shell commands as any non-root user. This issue only affected Ubuntu 16.04 ESM. (CVE-2020-8794)
- Record
USN-4875-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
opensmtpdDebian:12 |
before 6.6.4p1-1 | 6.6.4p1-1 |
opensmtpdDebian:13 |
before 6.6.4p1-1 | 6.6.4p1-1 |
opensmtpdDebian:14 |
before 6.6.4p1-1 | 6.6.4p1-1 |
opensmtpdUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 5.3.3p1-45.4.1p1-15.4.1p1-1ubuntu0.1~esm1 |
None known |
opensmtpdUbuntu:Pro:16.04:LTS |
before 5.7.3p2-1ubuntu0.1~esm2, plus listed versions 5.4.2p1-45.7.3p1-15.7.3p2-15.7.3p2-1ubuntu0.1~esm1 |
5.7.3p2-1ubuntu0.1~esm2 |
opensmtpdUbuntu:18.04:LTS |
before 6.0.3p1-1ubuntu0.2, plus listed versions 6.0.2p1-2build16.0.3p1-16.0.3p1-1build16.0.3p1-1ubuntu0.1 |
6.0.3p1-1ubuntu0.2 |
opensmtpdUbuntu:20.04:LTS |
before 6.6.4p1-1, plus listed versions 6.0.3p1-66.0.3p1-6build16.6.1p1-16.6.1p1-36.6.1p1-46.6.1p1-56.6.2p1-1 |
6.6.4p1-1 |
opensmtpdUbuntu:18.04:LTS From an advisory covering 2 CVEs |
before 6.0.3p1-1ubuntu0.2, plus listed versions 6.0.2p1-2build16.0.3p1-16.0.3p1-1build16.0.3p1-1ubuntu0.1 |
6.0.3p1-1ubuntu0.2 |
opensmtpdUbuntu:Pro:14.04:LTS From an advisory covering 3 CVEs |
before 5.4.1p1-1ubuntu0.1~esm1, plus listed versions 5.3.3p1-45.4.1p1-1 |
5.4.1p1-1ubuntu0.1~esm1 |
opensmtpdUbuntu:Pro:16.04:LTS From an advisory covering 3 CVEs |
before 5.7.3p2-1ubuntu0.1~esm2, plus listed versions 5.4.2p1-45.7.3p1-15.7.3p2-15.7.3p2-1ubuntu0.1~esm1 |
5.7.3p2-1ubuntu0.1~esm2 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | OpenSMTPD 6.6.3 - Arbitrary File Read | 2020-02-26 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, Exploit-DB, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-8793 is a medium vulnerability (CVSS 4.7) in Opensmtpd, published February 25, 2020. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 58th percentile. Fixed in opensmtpd 6.6.4p1-1.
References
openbsd.org/security.html
openwall.com/lists/oss-security/2020/02/24/4
seclists.org/fulldisclosure/2020/Feb/28
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E
usn.ubuntu.com/4294-1
nvd.nist.gov/vuln/detail/CVE-2020-8793
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lists.fedoraproject.org/archives/list/[email protected]/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E
github.com/advisories/GHSA-m2cf-xghm-rxmc
security-tracker.debian.org/tracker/CVE-2020-8793
ubuntu.com/security/CVE-2020-8793
ubuntu.com/security/notices/USN-4294-1
ubuntu.com/security/notices/USN-4875-1
cve.org/CVERecord?id=CVE-2020-8793
ubuntu.com/security/CVE-2020-8794
ubuntu.com/security/CVE-2020-7247