CVE-2022-26133
📋 TL;DR
This vulnerability allows remote, unauthenticated attackers to execute arbitrary code on Atlassian Bitbucket Data Center instances via Java deserialization in the SharedSecretClusterAuthenticator component. Attackers can gain full control of affected systems. Organizations running vulnerable versions of Bitbucket Data Center are affected.
💻 Affected Systems
- Atlassian Bitbucket Data Center
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining root/admin privileges, data exfiltration, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to data theft, service disruption, and potential ransomware deployment.
If Mitigated
Limited impact if network segmentation and strict access controls prevent external access, though internal threats remain.
🎯 Exploit Status
Java deserialization vulnerabilities are well-understood with available exploit frameworks. The CVE references known Hazelcast vulnerabilities (CVE-2016-10750) suggesting similar exploitation patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.6.14, 7.17.6, 7.18.4, 7.19.4, or later versions
Restart Required: Yes
Instructions:
1. Download patched version from Atlassian downloads. 2. Backup current installation and database. 3. Stop Bitbucket service. 4. Install patched version. 5. Restart Bitbucket service. 6. Verify functionality.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict network access to Bitbucket cluster communication ports (default 5701-5708 for Hazelcast) to trusted nodes only.
iptables -A INPUT -p tcp --dport 5701:5708 -s <trusted_ip> -j ACCEPT
iptables -A INPUT -p tcp --dport 5701:5708 -j DROP
Disable Cluster Authentication
allConfigure Bitbucket to use alternative authentication methods or disable cluster communication if not required.
Edit bitbucket.properties: hazelcast.network.tcpip.enabled=false
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Bitbucket cluster traffic from untrusted networks
- Deploy web application firewall (WAF) with Java deserialization protection rules
🔍 How to Verify
Check if Vulnerable:
Check Bitbucket version via admin interface or by examining installation directory. Verify if running in affected version range.Check Version:
cat /path/to/bitbucket/atlassian-bitbucket/WEB-INF/classes/build.properties | grep versionVerify Fix Applied:
Confirm version is 7.6.14, 7.17.6, 7.18.4, 7.19.4 or later. Test cluster communication functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in logs
- Unexpected network connections to cluster ports
- Suspicious process execution from Bitbucket service account
Network Indicators:
- Unexpected traffic to Hazelcast ports (5701-5708) from untrusted sources
- Java serialized object streams in network traffic
SIEM Query:
source="bitbucket.log" AND ("deserialization" OR "SerializationException" OR "InvalidClassException")🔗 References
- https://confluence.atlassian.com/security/multiple-products-security-advisory-hazelcast-vulnerable-to-remote-code-execution-cve-2016-10750-1116292387.html
- https://jira.atlassian.com/browse/BSERV-13173
- https://confluence.atlassian.com/security/multiple-products-security-advisory-hazelcast-vulnerable-to-remote-code-execution-cve-2016-10750-1116292387.html
- https://jira.atlassian.com/browse/BSERV-13173
