CVE-2023-40019

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CVE

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to version 1.10.10, FreeSWITCH allows authorized users to cause a denial of service attack by sending re-INVITE with SDP containing duplicate codec names. When a call in FreeSWITCH completes codec negotiation, the codec_string channel variable is set with the result of the negotiation.

On a subsequent re-negotiation, if an SDP is offered that contains codecs with the same names but with different formats, there may be too many codec matches detected by FreeSWITCH leading to overflows of its internal arrays. By abusing this vulnerability, an attacker is able to corrupt stack of FreeSWITCH leading to an undefined behavior of the system or simply crash it. Version 1.10.10 contains a patch for this issue.

HIGH · CVSS 7.5 EPSS 0.00283

Act now

Public exploit or PoC is available
SSVC automatable: yes - attacks can be scripted at scale
CVSS base score ≥ 7.0

Sigma rules0 YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Vulners Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2023-40019, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

View attack path from CVE-2023-40019

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ATT&CK techniques

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1498.001 · Direct Network Flood T1498.002 · Reflection Amplification T1499 · Endpoint Denial of Service T1499.001 · OS Exhaustion Flood T1499.002 · Service Exhaustion Flood T1499.003 · Application Exhaustion Flood

▤ Build a SIEM detection for these techniques

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CAPEC attack patterns

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-125 · Flooding CAPEC-CAPEC-130 · Excessive Allocation CAPEC-CAPEC-147 · XML Ping of the Death CAPEC-CAPEC-197 · Exponential Data Expansion CAPEC-CAPEC-229 · Serialized Data Parameter Blowup CAPEC-CAPEC-230 · Serialized Data with Nested Payloads CAPEC-CAPEC-231 · Oversized Serialized Data Payloads CAPEC-CAPEC-469 · HTTP DoS CAPEC-CAPEC-482 · TCP Flood CAPEC-CAPEC-486 · UDP Flood CAPEC-CAPEC-487 · ICMP Flood CAPEC-CAPEC-488 · HTTP Flood

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Weakness Classification

CWE-770Allocation of Resources Without Limits or Throttling

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Affected Products & Versions

freeswitch< 1.10.10

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Public Exploits & PoCs

These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted.

pocPublic PoC (nvd-reference)

pocgithub.com · GHSA-gjj5-79p2-9g3qgithub.com

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Scoring & Timeline

7.5

HIGH · CVSS v3.1 · [email protected]

View on NVD

Attack Vector

Network Adjacent Local Physical

Attack Complexity

Low High

Privileges Required

None Low High

User Interaction

None Required

Scope

Unchanged Changed

Confidentiality

None Low High

Integrity

None Low High

Availability

None Low High

Published to NVD15 Sep 2023 · 08:15 PM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC triage · cisa-vulnrichment

Exploitation

poc

Automatable

yes

Technical impact

partial

SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

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References & Sources

Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.

https://github.com/signalwire/freeswitch/releases/tag/v1.10.10Release Notes