CVE-2022-31115
📋 TL;DR
This vulnerability in opensearch-ruby allows remote code execution through unsafe YAML deserialization when connecting to a malicious OpenSearch server. Attackers controlling an OpenSearch server can execute arbitrary code on client systems that connect to it. Only users of opensearch-ruby gem versions before 2.0.1 are affected.
💻 Affected Systems
- opensearch-ruby gem
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full remote code execution on client systems, allowing attackers to install malware, steal data, or pivot to other systems.
Likely Case
Arbitrary code execution on client machines when users connect to attacker-controlled OpenSearch servers.
If Mitigated
No impact if clients only connect to trusted OpenSearch servers or have upgraded to patched version.
🎯 Exploit Status
Exploitation requires attacker to control OpenSearch server that victim connects to; YAML deserialization RCE techniques are well-documented for Ruby.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.1
Vendor Advisory: https://github.com/opensearch-project/opensearch-ruby/security/advisories/GHSA-977c-63xq-cgw3
Restart Required: No
Instructions:
1. Update Gemfile to specify 'gem "opensearch-ruby", ">= 2.0.1"' 2. Run 'bundle update opensearch-ruby' 3. Verify update with 'bundle list | grep opensearch-ruby'
🔧 Temporary Workarounds
Restrict OpenSearch server connections
allOnly allow connections to trusted, internal OpenSearch servers to prevent connecting to malicious servers.
🧯 If You Can't Patch
- Implement network controls to restrict outbound connections to OpenSearch servers
- Monitor for connections to unknown or external OpenSearch servers
🔍 How to Verify
Check if Vulnerable:
Check Gemfile.lock or run 'bundle list | grep opensearch-ruby' and verify version is below 2.0.1Check Version:
bundle list | grep opensearch-rubyVerify Fix Applied:
Confirm opensearch-ruby version is 2.0.1 or higher using 'bundle list | grep opensearch-ruby'📡 Detection & Monitoring
Log Indicators:
- Unexpected YAML parsing errors
- Connections to unknown OpenSearch servers
Network Indicators:
- Outbound connections to non-standard OpenSearch servers
- YAML content in HTTP responses from OpenSearch
SIEM Query:
source="application.log" AND "YAML.load" AND "opensearch"🔗 References
- https://github.com/opensearch-project/opensearch-ruby/pull/77
- https://github.com/opensearch-project/opensearch-ruby/security/advisories/GHSA-977c-63xq-cgw3
- https://staaldraad.github.io/post/2021-01-09-universal-rce-ruby-yaml-load-updated/
- https://github.com/opensearch-project/opensearch-ruby/pull/77
- https://github.com/opensearch-project/opensearch-ruby/security/advisories/GHSA-977c-63xq-cgw3
- https://staaldraad.github.io/post/2021-01-09-universal-rce-ruby-yaml-load-updated/
