CVE-2025-47779
📋 TL;DR
This vulnerability in Asterisk PBX allows authenticated attackers to spoof user identities when sending SIP MESSAGE requests, enabling them to send spam messages that appear to come from trusted sources. All Asterisk users running affected versions are impacted, including administrators following security best practices. The flaw enables social engineering, phishing, and spam attacks through message spoofing.
💻 Affected Systems
- Asterisk
- certified-asterisk
📦 What is this software?
Asterisk by Sangoma
Asterisk by Sangoma
Asterisk by Sangoma
Asterisk by Sangoma
⚠️ Risk & Real-World Impact
Worst Case
Attackers impersonate administrators or trusted entities to send malicious messages, leading to successful phishing campaigns, credential theft, or unauthorized system access through social engineering.
Likely Case
Spam messages sent from spoofed trusted sources, potentially leading to confusion, social engineering attempts, and reputational damage to the impersonated entities.
If Mitigated
Limited impact if message filtering is in place and users are trained to verify message authenticity, though spoofed messages may still bypass some controls.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once authentication is obtained. The vulnerability is in the SIP protocol handling, making weaponization likely given the impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Asterisk 18.26.2, 20.14.1, 21.9.1, 22.4.1; certified-asterisk 18.9-cert14, 20.7-cert5
Vendor Advisory: https://github.com/asterisk/asterisk/security/advisories/GHSA-2grh-7mhv-fcfw
Restart Required: Yes
Instructions:
1. Identify your Asterisk version using 'asterisk -V'. 2. Download and install the appropriate patched version from the Asterisk website or your distribution's repository. 3. Restart the Asterisk service to apply the fix.
🔧 Temporary Workarounds
Disable SIP MESSAGE functionality
allPrevent exploitation by disabling SIP MESSAGE requests in the Asterisk configuration
Edit pjsip.conf or sip.conf and set 'allowmessage = no' in relevant sections
Restrict SIP authentication
allImplement stricter SIP authentication controls and monitor for unusual MESSAGE requests
Configure authentication realms and monitor logs for suspicious activity
🧯 If You Can't Patch
- Implement network segmentation to isolate Asterisk servers from untrusted networks
- Deploy message filtering and user awareness training to identify spoofed messages
🔍 How to Verify
Check if Vulnerable:
Check Asterisk version with 'asterisk -V' and compare against affected versions. Review configuration for SIP MESSAGE settings.Check Version:
asterisk -VVerify Fix Applied:
Confirm version is updated to patched release and test SIP MESSAGE authentication alignment.📡 Detection & Monitoring
Log Indicators:
- Unusual SIP MESSAGE requests, authentication mismatches in logs, messages from unexpected sources
Network Indicators:
- SIP MESSAGE traffic with spoofed From headers, abnormal message volume
SIEM Query:
Search for SIP protocol events with message type and authentication failures or mismatched user identities