CVE-2007-4521
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 · uneditedAsterisk Open Source 1.4.5 through 1.4.11, when configured to use an IMAP voicemail storage backend, allows remote attackers to cause a denial of service via an e-mail with an "invalid/corrupted" MIME body, which triggers a crash when the recipient listens to voicemail.
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 confidenceAsterisk Open Source versions 1.4.5 through 1.4.11 contain a denial of service vulnerability in the IMAP voicemail storage backend. When an attacker sends an email with an invalid or corrupted MIME body to the voicemail system, it triggers a crash in Asterisk when the recipient attempts to listen to the voicemail message.
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= 1.4.5= 1.4.6= 1.4.7= 1.4.8= 1.4.9= 1.4.10= 1.4.11CVSS 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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Determine Asterisk versionRun `asterisk -V` or `asterisk -vvv` to display version information, or check the binary with `asterisk -V`. Alternatively, check the package manager for installed version.Affected if The installed version is between 1.4.5 and 1.4.11 inclusive.
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Identify voicemail configuration fileLocate the Asterisk voicemail configuration file, typically found at /etc/asterisk/voicemail.conf or /etc/asterisk/voicemail.conf.oldAffected if Configuration file exists and contains IMAP-related settings.
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Verify IMAP voicemail storage is enabledIn the voicemail configuration file, look for IMAP settings such as `imapserver`, `imapport`, or lines beginning with `imap` under the voicemail context. Also check for `mailcmd` pointing to an IMAP utility.Affected if IMAP-based voicemail storage is configured and active in the voicemail configuration.
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Confirm voicemail users are configuredIn the voicemail configuration file, check for voicemail boxes defined in any context. Each context with voicemail users would trigger the vulnerable code path when using IMAP storage.Affected if Voicemail boxes exist and IMAP storage is enabled.
You are affected if Asterisk version is between 1.4.5 and 1.4.11 AND IMAP voicemail storage is enabled in the configuration.
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 Asterisk to version 1.4.12 or later, which contains the patch for this vulnerability. If immediate upgrade is not possible, consider disabling IMAP voicemail storage temporarily or implementing mail filtering before the Asterisk server.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2007-4521 — 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-2007-4521 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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- 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
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