CVE-1999-0204
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 · uneditedSendmail 8.6.9 allows remote attackers to execute root commands, using ident.
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 · moderate confidenceSendmail version 8.6.9 contains a vulnerability in its ident protocol handling that allows remote attackers to execute commands with root privileges. The ident service (RFC 1413) is used to query user information about TCP connections, and improper validation in this version enables arbitrary command execution.
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= 8.6.9CVSS 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
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:N/C:C/I:C/A:C
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.
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Identify Sendmail versionRun `sendmail -V` or `sendmail -d0.1` to display the installed Sendmail version numberAffected if The version displayed is exactly 8.6.9
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Verify ident lookup configurationCheck the Sendmail configuration file (typically /etc/sendmail.cf or /etc/mail/sendmail.cf) for the 'O' option controlling ident lookups. Look for lines containing 'IdentProtocol' or 'F-W' flags related to identAffected if The configuration enables ident lookups (the default behavior in vulnerable versions)
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Confirm ident service availabilityQuery the ident service on the target system by running `ident 25` or using `netcat` to port 113 on the mail server, or check if /etc/inetd.conf or systemd services expose the ident serviceAffected if The ident service (port 113) is accessible and responds to queries
You are affected if Sendmail version 8.6.9 is installed AND the ident lookup feature is enabled in the configuration, allowing remote attackers to potentially execute commands with root privileges through malformed ident protocol responses.
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.
dbcve · scopedUpgrade Sendmail to a patched version (8.6.10 or later) or consider migrating to a modern mail server solution, as Sendmail 8.6.9 is severely outdated (circa 1996-1997). If ident is not required, disable the ident lookup feature in Sendmail configuration as an immediate workaround.
Latest stable Sendmail release (8.17.x or current) - legacy 8.6.x is no longer supported
- 1. Back up the current Sendmail configuration (/etc/mail/ or /etc/sendmail.cf)
- 2. Stop the Sendmail service
- 3. Obtain the latest stable Sendmail release from official sources (sendmail.org)
- 4. Compile and install the new Sendmail version
- 5. Restore or update the Sendmail configuration as needed
- 6. Restart the Sendmail service
- 7. Verify the service is running correctly and test mail functionality
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0204 — 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-1999-0204 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
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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