FedoraOperating system · Fedoraproject
CVE-2020-7046
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedlib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated by the unauthenticated triggering of a submission-login infinite loop.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceDovecot's lib-smtp library in submission-login and lmtp services mishandles truncated UTF-8 data in command parameters, causing an infinite loop when malformed input is received. This is remotely exploitable without authentication, resulting in denial of service via service hang.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FedoraOperating system
= 30= 31>= 2.3.9, < 2.3.9.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify installed Dovecot versionRun 'dovecot --version' or check the package manager (e.g., 'rpm -q dovecot' or 'dpkg -l dovecot')Affected if The version is 2.3.9, 2.3.9.1, or 2.3.9.2 (versions >= 2.3.9 and < 2.3.9.3)
-
Confirm submission-login service is in useCheck dovecot configuration files (dovecot.conf, master.cf) for 'submission-login' or port 587 configuration, or run 'netstat -tlnp | grep 587' or 'ss -tlnp | grep 587' to see if port 587 is listeningAffected if The submission service (port 587) is enabled and listening for connections
-
Confirm LMTP service is in useCheck dovecot configuration for 'lmtp' service, or run 'netstat -tlnp | grep 25' or 'ss -tlnp | grep 25' to check if LMTP port is listeningAffected if The LMTP service (typically port 24 or 25) is enabled and listening for connections
-
Identify Fedora version (if applicable)Run 'cat /etc/fedora-release' or 'rpm -q fedora-release'Affected if Running Fedora 30 or 31 with dovecot installed
You are affected if your dovecot version is 2.3.9.x (where x < 3) AND either the submission-login or LMTP service is enabled and exposed to network connections.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data2.3.9.3
Upgrade Dovecot to version 2.3.9.3 or later. If immediate upgrade is not feasible, restrict or disable external access to submission (port 587) and LMTP services to reduce attack surface.
Fix this in Fedora
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-7046 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-7046 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data