AsteriskApplication · Digium

CVE-2012-4737

MEDIUM · 6.0 CVSS v2.0 Published 2012-08-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
Remediation priority · Elevated
Remotely reachable 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
channels/chan_iax2.c in Asterisk Open Source 1.8.x before 1.8.15.1 and 10.x before 10.7.1, Certified Asterisk 1.8.11 before 1.8.11-cert7, Asterisk Digiumphones 10.x.x-digiumphones before 10.7.1-digiumphones, and Asterisk Business Edition C.3.x before C.3.7.6 does not enforce ACL rules during certain uses of peer credentials, which allows remote authenticated users to bypass intended outbound-call restrictions by leveraging the availability of these credentials.

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 channel driver (channels/chan_iax2.c) in Asterisk fails to enforce ACL rules during certain operations using peer credentials. This allows authenticated remote users who possess valid peer credentials to bypass configured outbound-call restrictions, potentially placing unauthorized calls at the expense of the organization.

MitigationUpgrade Asterisk to version 1.8.15.1/10.7.1 or the corresponding certified/Business Edition fixed versions. Additionally, review and harden ACL configurations around IAX2 peers and consider rotating compromised credentials.

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:= 1.8.0= 1.8.1= 1.8.1.1= 1.8.1.2= 1.8.2= 1.8.2.1= 1.8.2.2= 1.8.2.3= 1.8.2.4= 1.8.3= 1.8.3.1= 1.8.3.2
Certified AsteriskApplication
Affected:= 1.8.11

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
M
Authentication
Single
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:M/Au:S/C:P/I:P/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 checks

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

  1. Determine Asterisk version
    Run `asterisk -V` or `asterisk -vv` from command line, or enter Asterisk CLI and run `core show version`
    Affected if The installed version matches 1.8.0 through 1.8.3.2, or is 1.8.11 certified version, as listed in affected versions
  2. Verify IAX2 module is loaded
    Enter Asterisk CLI and run `module show like iax` or `iax2 show version`
    Affected if The IAX2 channel driver module (chan_iax2) is loaded and active
  3. Confirm IAX2 peers exist
    Enter Asterisk CLI and run `iax2 show peers` or inspect the IAX configuration file (typically /etc/asterisk/iax.conf) for peer definitions
    Affected if One or more IAX2 peers are configured with valid credentials
  4. Check for ACL rules on IAX2
    Inspect /etc/asterisk/iax.conf for `deny` and `permit` directives within peer definitions, or run `iax2 show peer <peername>` in CLI to view ACL settings
    Affected if ACL rules (deny/permit) are defined but were being bypassed due to this vulnerability

You are affected if you run an affected Asterisk version (1.8.0-1.8.3.2 or certified 1.8.11) with IAX2 peers configured, particularly if those peers rely on ACLs to restrict outbound calls.

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 version 1.8.15.1/10.7.1 or the corresponding certified/Business Edition fixed versions. Additionally, review and harden ACL configurations around IAX2 peers and consider rotating compromised credentials.

Fix this in Asterisk Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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Scan for this in your stack

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dbcve dependency scanner

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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-2012-4737 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
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