CVE-2023-30463
📋 TL;DR
CVE-2023-30463 is an integer overflow vulnerability in Altran picoTCP's IPv6 implementation that allows memory corruption when processing large ICMPv6 packets. This affects systems using picoTCP with Ethernet support where packets exceeding 65495 bytes may be received, potentially causing denial of service. The vulnerability primarily impacts embedded systems and IoT devices using this TCP/IP stack.
💻 Affected Systems
- Altran picoTCP
📦 What is this software?
Picotcp by Altran
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, though memory corruption typically results in denial of service.
Likely Case
Denial of service through system crash or reboot when processing malicious ICMPv6 packets.
If Mitigated
Limited impact if network filtering blocks large ICMPv6 packets or if IPv6 is disabled.
🎯 Exploit Status
Proof of concept demonstrates denial of service. Exploitation requires sending specially crafted large ICMPv6 packets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.7.1 or later
Vendor Advisory: https://github.com/tass-belgium/picotcp/releases
Restart Required: Yes
Instructions:
1. Update picoTCP to version 1.7.1 or later. 2. Recompile applications using the library. 3. Restart affected systems.
🔧 Temporary Workarounds
Filter large ICMPv6 packets
linuxConfigure network devices to drop ICMPv6 packets larger than 65495 bytes
iptables -A INPUT -p ipv6-icmp --icmpv6-type any -m length --length 65496: -j DROP
Disable IPv6 if not needed
linuxTurn off IPv6 functionality in systems where it's not required
sysctl -w net.ipv6.conf.all.disable_ipv6=1
sysctl -w net.ipv6.conf.default.disable_ipv6=1
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems
- Deploy intrusion prevention systems to detect and block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check picoTCP version in source code or compiled binaries. Versions ≤1.7.0 are vulnerable.Check Version:
grep -r "PICO_VERSION" in source code or check library metadataVerify Fix Applied:
Verify picoTCP version is ≥1.7.1 and check for proper bounds checking in pico_ipv6_alloc function.📡 Detection & Monitoring
Log Indicators:
- System crashes, reboots, or kernel panics after receiving ICMPv6 traffic
- Memory corruption errors in system logs
Network Indicators:
- Large ICMPv6 packets (>65495 bytes) directed at vulnerable systems
- Unusual ICMPv6 traffic patterns
SIEM Query:
source_ip=* AND dest_ip=vulnerable_system AND protocol=ICMPv6 AND packet_size>65495