CVE-2025-1675
📋 TL;DR
CVE-2025-1675 is an out-of-bounds read vulnerability in the dns_copy_qname function of Zephyr RTOS's DNS implementation. This allows attackers to read sensitive memory contents when processing malicious DNS responses. Systems running Zephyr RTOS with DNS functionality enabled are affected.
💻 Affected Systems
- Zephyr RTOS
📦 What is this software?
Zephyr by Zephyrproject
⚠️ Risk & Real-World Impact
Worst Case
Information disclosure leading to memory content leakage, potentially exposing cryptographic keys, credentials, or other sensitive data stored in adjacent memory.
Likely Case
Denial of service through system crashes or information disclosure of limited memory regions.
If Mitigated
Minimal impact if DNS functionality is disabled or proper memory isolation is implemented.
🎯 Exploit Status
Exploitation requires sending malicious DNS responses to the target system. No authentication needed if DNS is exposed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Zephyr security advisory for specific fixed version
Vendor Advisory: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m84-5hfw-m8v4
Restart Required: Yes
Instructions:
1. Update Zephyr RTOS to the patched version. 2. Rebuild and redeploy affected firmware. 3. Restart devices running the updated firmware.
🔧 Temporary Workarounds
Disable DNS functionality
allDisable DNS client functionality in Zephyr configuration if not required
Set CONFIG_DNS_RESOLVER=n in project configuration
🧯 If You Can't Patch
- Implement network segmentation to isolate DNS traffic to trusted sources only
- Monitor for abnormal DNS response patterns or system crashes
🔍 How to Verify
Check if Vulnerable:
Check if DNS functionality is enabled in Zephyr configuration and version is unpatchedCheck Version:
Check Zephyr version in build configuration or device firmware versionVerify Fix Applied:
Verify Zephyr version includes the security patch and DNS functionality works normally📡 Detection & Monitoring
Log Indicators:
- System crashes or reboots during DNS operations
- Memory access violation logs
Network Indicators:
- Unusual DNS response patterns from untrusted sources
- DNS responses with malformed QNAME fields
SIEM Query:
DNS response size anomalies OR system crash events during DNS resolution