Phones & PBX
Keeping office phone systems patched, secure, and safe from scammers running up the bill.
- Phones & PBXSecurity alert
FreeSWITCH phone systems need version 1.11.3 now — CVE-2026-116779 is being exploited
A critical FreeSWITCH flaw that allows command execution through SIP text messages is on CISA's exploited list. Here's who is affected and what to do.
- Field notes
Field note: the desk phone that could call out but never rang
A SIP phone showed Registered and placed calls fine, but incoming calls never reached it. The firewall was quietly forgetting the phone's NAT session after 40 seconds.
- Field notes
Field note: a dying Switchvox appliance, a Hyper-V rebuild, and the 32-second drops that weren't the hardware
A Switchvox box with a failing network port got moved to a Hyper-V VM in an afternoon. The calls kept dropping at 32 seconds anyway, and a packet capture showed the real cause was one empty setting.
- Field notes
Field note: clearing more than 60,000 blocked IPs across 13 phone systems
What I learned clearing years of accumulated blocked-IP lists from a fleet of on-prem phone systems, from crashed web interfaces to a browser quirk that quietly slowed everything down.
- Phones & PBX
Kari's Law and RAY BAUM's Act: the 911 rules for business phone systems
If your office has a multi-line phone system, federal rules cover how 911 calls must work. Here's what they require, which systems they apply to, and how to check yours.
- Useful scripts
One console command to see how many IPs your Switchvox is blocking
A single read-only command you can paste into Chrome's console to count your Switchvox blocked IP list, and what the number tells you.
- Useful scripts
Clearing a Switchvox blocked IP list from Chrome's console
A step-by-step way to export and clear thousands of Switchvox blocked IPs through the built-in API, without clicking through the list one row at a time.
- Phones & PBXSecurity alert
Patch Sangoma Switchvox now — an unauthenticated flaw is being exploited
A critical, unauthenticated SQL injection in Switchvox SMB is being actively exploited to plant reverse shells. Here's what's affected and what to do today.
- Phones & PBX
Locking down an on-prem phone system that's exposed to the internet
Scanners find internet-facing phone systems within minutes. Here's how to cut the exposure, stop toll fraud, and keep the admin interface off the public internet.