CVE-2008-5006
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 · uneditedsmtp.c in the c-client library in University of Washington IMAP Toolkit 2007b allows remote SMTP servers to cause a denial of service (NULL pointer dereference and application crash) by responding to the QUIT command with a close of the TCP connection instead of the expected 221 response code.
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 confidenceThe c-client library in UW IMAP Toolkit 2007b contains a NULL pointer dereference vulnerability in smtp.c. When a remote SMTP server responds to a QUIT command by closing the TCP connection instead of sending the expected 221 response code, the application attempts to dereference a NULL pointer, causing a crash and denial of service.
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= 2007bCVSS 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
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 if UW IMAP Toolkit c-client library is installedLook for imapd, ipopd, or related binaries in /usr/lib, /usr/local/lib, or check for package named 'uw-imap' or 'imap-2007' using package manager (dpkg -l, rpm -qa)Affected if Package or binary named 'uw-imap' or 'imap' version 2007b is found on the system
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Determine the exact version of the IMAP toolkitCheck the library version by running 'strings libc-client.a 2>/dev/null | grep -i 2007' or check imapd version with 'imapd -v' or check /usr/share/doc/imap/ for version filesAffected if Version is confirmed to be exactly 2007b
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Identify if SMTP client functionality is in useCheck for processes using the c-client library for SMTP: look for smtpd, sendmail, or custom applications linking against libc-client. Use 'ldd <binary>' to see if it links to libc-clientAffected if SMTP daemon or client application is running that links against the UW c-client library
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Check for crash logs related to SMTP QUIT handlingReview system logs (/var/log/mail.log, /var/log/maillog, /var/log/messages) for segfaults, crashes, or NULL pointer dereferences occurring after QUIT commands from remote SMTP serversAffected if Crashes are logged occurring after SMTP QUIT transactions with remote servers
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Verify if exposed to untrusted remote SMTP serversCheck configuration of the SMTP service to determine if it accepts connections from remote untrusted servers. Review configuration files in /etc or application config for 'remote' or 'network' settingsAffected if The SMTP service is configured to accept connections from remote untrusted servers that could send malformed responses
The system is affected if UW IMAP Toolkit version 2007b is installed with an SMTP client/service using the c-client library and that service is exposed to remote servers that could close connections without sending the 221 response to QUIT commands.
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 dataUpgrade to a patched version of the University of Washington IMAP Toolkit that properly handles missing or malformed SMTP responses, or implement connection state validation before dereferencing response pointers.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2008-5006 — 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-2008-5006 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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- Version or environment caveats, and links to real fixes
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