CVE-2025-30195
📋 TL;DR
This vulnerability in PowerDNS Recursor allows attackers to publish malicious DNS zones containing specific Resource Record Sets. Processing these records causes illegal memory accesses that crash the Recursor service, leading to denial of service. Organizations running vulnerable PowerDNS Recursor instances are affected.
💻 Affected Systems
- PowerDNS Recursor
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete DNS resolution outage for all clients relying on the vulnerable Recursor, potentially disrupting critical network services and applications.
Likely Case
Intermittent DNS service disruptions affecting user connectivity and application functionality until the Recursor is restarted.
If Mitigated
Limited impact with proper network segmentation and monitoring allowing quick detection and recovery.
🎯 Exploit Status
Attack requires publishing malicious DNS zones which could be done through compromised domains or DNS providers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.2.1
Vendor Advisory: https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2025-01.html
Restart Required: Yes
Instructions:
1. Download PowerDNS Recursor 5.2.1 from official repository. 2. Stop the Recursor service. 3. Install the new version. 4. Restart the Recursor service. 5. Verify service is running correctly.
🔧 Temporary Workarounds
Restrict Zone Transfers
allLimit which DNS zones your Recursor will accept and cache from untrusted sources
# Configure allow-from and allow-from-file directives in recursor.conf
Implement Rate Limiting
allAdd rate limiting to prevent rapid exploitation attempts
# Configure max-cache-entries and max-negative-ttl in recursor.conf
🧯 If You Can't Patch
- Implement network segmentation to isolate Recursor instances
- Deploy additional monitoring and alerting for Recursor crashes
🔍 How to Verify
Check if Vulnerable:
Check PowerDNS Recursor version using 'rec_control version' or 'pdns_recursor --version'Check Version:
rec_control versionVerify Fix Applied:
Verify version is 5.2.1 or higher and monitor for Recursor crashes after patch📡 Detection & Monitoring
Log Indicators:
- Recursor crash logs
- Segmentation fault errors
- Unexpected service restarts
- Memory access violation messages
Network Indicators:
- DNS resolution failures
- Increased timeout errors from clients
- Unusual DNS query patterns
SIEM Query:
source="powerdns" AND ("segmentation fault" OR "crash" OR "illegal memory access")