FreePBX up to 17.0.10 publicKeySave AJAX endpoint Backup.class.php improper authorization

Summaryinfo

A vulnerability identified as very critical has been detected in FreePBX up to 17.0.10. This vulnerability affects unknown code of the file Backup.class.php of the component publicKeySave AJAX endpoint. The manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-73664. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in FreePBX up to 17.0.10. This issue affects some unknown functionality of the file Backup.class.php of the component publicKeySave AJAX endpoint. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

FreePBX is an open source IP PBX. From 17.0.5.34 until 17.0.11, the publicKeySave AJAX endpoint in Backup.class.php accepts an authenticated administrator's SSH public key and appends it to /home/asterisk/.ssh/authorized_keys for the asterisk system user without reliably enforcing backup-only command and source restrictions. The key grants persistent shell access that can execute arbitrary commands, access FreePBX and call data, modify system files, and disrupt services. This issue is fixed in version 17.0.11.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-73664 since 08/13/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/14/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

By approaching the search of inurl:Backup.class.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 17.0.11 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• FreePBX

Version

• 17.0.0
• 17.0.1
• 17.0.2
• 17.0.3
• 17.0.4
• 17.0.5
• 17.0.6
• 17.0.7
• 17.0.8
• 17.0.9
• 17.0.10

License

• open-source

CPE 2.3info

• 🔒
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CPE 2.2info

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