AsteriskApplication

CVE-2009-2346

HIGH · 7.8 CVSS v2.0 Published 2009-09-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
The IAX2 protocol implementation in Asterisk Open Source 1.2.x before 1.2.35, 1.4.x before 1.4.26.2, 1.6.0.x before 1.6.0.15, and 1.6.1.x before 1.6.1.6; Business Edition B.x.x before B.2.5.10, C.2.x before C.2.4.3, and C.3.x before C.3.1.1; and s800i 1.3.x before 1.3.0.3 allows remote attackers to cause a denial of service (call-number exhaustion) by initiating many IAX2 message exchanges, a related issue to CVE-2008-3263.

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 confidence

The IAX2 (Inter-Asterisk Exchange) protocol implementation in multiple Asterisk versions contains a vulnerability allowing remote attackers to exhaust call numbers by initiating many IAX2 message exchanges, causing denial of service. This is a resource exhaustion issue in the IAX2 channel driver.

MitigationUpgrade Asterisk to the patched versions (1.2.35+, 1.4.26.2+, 1.6.0.15+, 1.6.1.6+, Business Edition B.2.5.10+, C.2.4.3+, C.3.1.1+, s800i 1.3.0.3+) to resolve the call-number exhaustion vulnerability.

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
AsteriskApplication
Affected:= b.1.3.2= b.1.3.3= b.2.2.0= b.2.2.1= b.2.3.1= b.2.3.2= b.2.3.3= b.2.3.4= b.2.3.5= b.2.3.6= b.2.5.1= b.2.5.3
Open SourceApplication
Affected:= 1.2.0= 1.2.1= 1.2.2= 1.2.3= 1.2.4= 1.2.5= 1.2.6= 1.2.7= 1.2.7.1= 1.2.8= 1.2.9= 1.2.9.1
OpensourceApplication
Affected:= 1.4.23.2= 1.4.24= 1.4.24.1= 1.4.26= 1.4.26.1
AsteriskApplication
Affected:= 1.6.1= 1.6.1.4
Appliance S800iHardware / appliance
Affected:= 1.3= 1.3.0.2

CVSS 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
Complete

AV:N/AC:L/Au:N/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Asterisk version
    Run 'asterisk -V' or 'asterisk -vvv' at the command line to display the installed version
    Affected if The version matches one of the affected versions: Asterisk b.1.3.x, b.2.2.x, b.2.3.x, b.2.5.x; Open Source 1.2.x through 1.2.9.1; Opensource 1.4.23.2 through 1.4.26.1; Sangoma 1.6.1 through 1.6.1.4; Appliance S800i 1.3.x
  2. Verify IAX2 module is loaded
    Execute 'module show' or 'iax2 show version' at the Asterisk CLI to confirm the IAX2 channel driver module is loaded
    Affected if The IAX2 module (chan_iax2.so) is loaded and running
  3. Check for active IAX2 peers or calls
    Run 'iax2 show peers' or 'iax2 show channels' at the Asterisk CLI to list configured IAX2 peers and active calls
    Affected if IAX2 peers exist and IAX2 protocol is in use, exposing the vulnerability surface
  4. Review IAX2 configuration
    Inspect the iax.conf configuration file (typically in /etc/asterisk/ or /etc/) for IAX2-related settings and ensure the service is actively listening on port 4569
    Affected if IAX2 is enabled and configured in the configuration file, meaning the service is exposed

A user is affected if they are running any of the listed vulnerable Asterisk versions AND have the IAX2 protocol enabled or loaded, as the resource exhaustion flaw requires an active IAX2 implementation to be exploited.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Asterisk to the patched versions (1.2.35+, 1.4.26.2+, 1.6.0.15+, 1.6.1.6+, Business Edition B.2.5.10+, C.2.4.3+, C.3.1.1+, s800i 1.3.0.3+) to resolve the call-number exhaustion vulnerability.

Fix this in Asterisk Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2009-2346 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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