More and More Attack on Redis Servers
Attackers compromised the outdated version Redis versions with exploit CVE-2017-9805 and drop ReddisWannaMine that installs cryptocurrency miner.
Imperva says“we’ve been hearing about more and more attacks on Redis servers”. To determine the significance of the attack researchers deployed a radius server based honeypot and within 24hours the servers registered the first attack.
Attackers set up a value key/ value pair in the memory and save it to the disk and force the file to run and download the file from external source. Imperva noticed the same key/ value pair on multiple servers which are a clear sign of botnet activity.
72K Open Redis servers
According to Shodan Query over port:6379 there are over 73,000 Redis servers were open to the Internet, which allows untrusted clients to access the Redis server.
According to the Imperva scan results, most of the server found to be infected with the malware “more than two-thirds of the open Redis servers contain malicious keys and three-quarters of the servers contain malicious values, suggesting that the server is infected.”
The Redis based honeypot exposed by Imperva target by a medium-sized botnet located at China (86% of IPs). The attacks included SQL injection, cross-site scripting, the malicious file uploads, remote code executions etc.
“We often see issues arise when people don’t read the documentation and migrate services to the cloud, without being aware of the consequences or the adequate measures that are needed to do so.”
- Don’t expose the Redis instance directly to the internet.
- Apply Authentication if possible.
- Don’t store sensitive data in clear text.
- Check the CPU usage and key values for infection.
- Make sure you run Redis with the minimal privileges necessary.