Open SourceApplication · Digium

CVE-2017-9372

HIGH · 7.5 CVSS v3.0 Published 2017-06-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
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
PJSIP, as used in Asterisk Open Source 13.x before 13.15.1 and 14.x before 14.4.1, Certified Asterisk 13.13 before 13.13-cert4, and other products, allows remote attackers to cause a denial of service (buffer overflow and application crash) via a SIP packet with a crafted CSeq header in conjunction with a Via header that lacks a branch parameter.

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

A buffer overflow vulnerability exists in PJSIP, the SIP stack used by Asterisk, where a malformed SIP packet containing a crafted CSeq header combined with a Via header missing the branch parameter triggers a buffer overflow, causing the application to crash and resulting in a denial of service.

MitigationUpgrade Asterisk to version 13.15.1 or later for the 13.x branch, 14.4.1 or later for the 14.x branch, or 13.13-cert4 or later for the Certified Asterisk 13.x branch. Additionally, consider implementing SIP traffic filtering at network boundaries to drop obviously malformed SIP packets.

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
Open SourceApplication
Affected:= 13.0.0= 13.1.0= 13.2.0= 13.3.0= 13.4.0= 13.5.0= 13.6.0= 13.7.0= 13.8.0= 13.8.1= 13.8.2= 13.9.0
Certified AsteriskApplication
Affected:= 13.13.0

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
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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. Check installed Asterisk version
    Run 'asterisk -V' or 'asterisk -rx "core show version"' to retrieve the installed version number
    Affected if Version is 13.0.0 through 13.9.0, or 13.13.0 (Certified), indicating it falls within the affected range
  2. Confirm PJSIP is the active SIP channel driver
    Run 'asterisk -rx "module show like pjsip"' and check if chan_pjsip.so is loaded, or check sip.conf for 'transport=pjsip' or 'pjsip.conf' existence
    Affected if PJSIP (chan_pjsip) is loaded and handling SIP traffic, as this vulnerability affects only the PJSIP stack
  3. Verify SIP peers or endpoints are configured
    Run 'asterisk -rx "pjsip show endpoints"' to list active PJSIP endpoints
    Affected if Endpoints exist, confirming Asterisk is accepting SIP connections via PJSIP which could receive malicious packets

If Asterisk version is 13.0.0-13.9.0 or 13.13.0 (Certified) AND PJSIP is loaded with configured endpoints, the environment is potentially affected by this buffer overflow vulnerability in the SIP stack.

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 13.15.1 or later for the 13.x branch, 14.4.1 or later for the 14.x branch, or 13.13-cert4 or later for the Certified Asterisk 13.x branch. Additionally, consider implementing SIP traffic filtering at network boundaries to drop obviously malformed SIP packets.

Fix this in Open Source Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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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-2017-9372 in production — separate from our analysis above.

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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
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