CVE-2023-40019Public exploitNetwork attack vector

Service crash via duplicate-codec SDP re-negotiation

Published Sep 15, 2023 · Updated Sep 25, 2024

Denial of service in FreeSWITCH before 1.10.10 allows remote authenticated users to crash the service via a crafted SIP re-INVITE. During repeated codec negotiation, the media core reuses the codec_string result and writes excessive same-name, different-format matches past internal array bounds, corrupting the stack. The attacker must be authorized to place or control a call and deliver a subsequent SIP re-INVITE; successful exploitation interrupts active telephony service, while the vendor reports undefined behavior beyond the crash.

CVSS severity6.5
Medium
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in FreeSWITCH before 1.10.10 allows remote authenticated users to crash the service via a crafted SIP re-INVITE. During repeated codec negotiation, the media core reuses the codec_string result and writes excessive same-name, different-format matches past internal array bounds, corrupting the stack. The attacker must be authorized to place or control a call and deliver a subsequent SIP re-INVITE; successful exploitation interrupts active telephony service, while the vendor reports undefined behavior beyond the crash.

The record

CVE
CVE-2023-40019
Published
Sep 15, 2023
Updated
Sep 25, 2024
Vendor
SignalWire
Product
FreeSWITCH
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.10.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SignalWire · FreeSWITCHversion=< 1.10.10

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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