VulnerabilityPublished 18 Mar 2024Updated 14 Nov 2024

CVE-2024-24539: fusionpbx

Affects fusionpbxSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 5.2.0 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.2.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Mar 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade fusionpbx/fusionpbx to 5.2.0.

Affected software

Product	Affected	Fixed in
GitHubfusionpbx/fusionpbx`pkg:github/fusionpbx/fusionpbx`Other threats	Affected <5.2.0	Fixed in 5.2.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-24539, organizations should upgrade FusionPBX to version 5.2.0 or later as soon as the patch becomes available, ensuring the session validation flaw is corrected. If you cannot patch yet, administrators should restrict external network access to FusionPBX management interfaces and SIP services using firewalls or VPNs to limit exposure to untrusted networks. Implementing intrusion detection and prevention systems (IDS/IPS) with rules targeting anomalous session requests can help detect and block exploitation attempts. Regularly monitoring system logs for unusual session activity or repeated failed session validations can provide early warning signs of exploitation attempts. Additionally, applying network segmentation to isolate telephony infrastructure from general corporate networks reduces the attack surface. Organizations should also maintain up-to-date backups of configuration and call data to facilitate rapid recovery in case of service disruption. Finally, staying informed through vendor advisories and security bulletins will ensure timely application of fixes and mitigations.

Description

FusionPBX before 5.2.0 does not validate a session.

Impact

The primary impact of this vulnerability is denial of service, which can disrupt telephony services relying on FusionPBX. Organizations using affected versions may experience service outages, degraded call quality, or complete loss of PBX functionality, impacting business communications and customer interactions. Since FusionPBX is often deployed in enterprise, call center, and service provider environments, availability issues can lead to operational downtime and financial losses. Although confidentiality and integrity are not directly affected, the disruption of voice services can indirectly impact business continuity and customer trust. The ease of remote exploitation without authentication increases the risk of opportunistic attacks, especially in environments exposed to the internet. However, the lack of known exploits in the wild suggests limited active targeting at this time. Organizations with critical telephony infrastructure should consider this vulnerability a moderate risk requiring timely remediation to prevent potential service disruptions.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Feb 2026, 09:35 UTC

Technical details

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