CVE-2023-22518: Atlassian Confluence Data Center and Server Improper Authorization Vulnerability

CVE-2023-22518 is an improper authorization vulnerability in Atlassian Confluence Data Center and Server. An unauthenticated attacker can exploit it to cause significant data loss. Confidentiality is not affected because the attacker cannot exfiltrate data. The issue has been used by ransomware operators, so organizations running Confluence should treat it as high priority and confirm all details against the vendor advisory.

This guidance helps IT and security teams understand the risk, locate affected instances, and reduce exposure until patches or other controls are in place.

How it works

The vulnerability is classified as CWE-863 (Improper Authorization). In this class of flaw, the application fails to correctly enforce access controls on certain operations. An unauthenticated remote attacker can invoke those operations without valid credentials or privileges.

According to the CISA summary, successful exploitation results in significant data loss on the Confluence instance. The attacker cannot read or steal data, so confidentiality impact is none; the primary harm is integrity and availability of content stored in Confluence. Exact request paths, parameters, or payload formats are not detailed here and must be confirmed from the vendor advisory. Because the attack requires no authentication, any internet-facing or poorly segmented Confluence server is a realistic target.

Am I affected? How to find it in your systems

Atlassian Confluence Data Center and Server are the products in scope. Confluence is commonly deployed as an internal wiki, knowledge base, or collaboration platform, often reachable via reverse proxies or load balancers. It may run on-premises, in private clouds, or in hybrid environments.

• Inventory all Confluence Data Center and Server instances by querying asset management systems, CMDB records, container registries, and network scans for typical Confluence ports and banners.
• Identify the exact product edition (Data Center versus Server) and version string from the administration console or installation files. Compare those versions against the fixed releases listed in the official Atlassian advisory; do not rely on version ranges stated elsewhere.
• Check configuration for any public or unauthenticated access paths. Review reverse-proxy and WAF logs for anomalous unauthenticated requests that target Confluence endpoints around the time of known exploitation activity.
• Look for signs of data loss or unexpected content deletion, empty spaces, or administrative alerts that could indicate successful abuse. Correlate with authentication logs showing no corresponding legitimate user sessions.

If you cannot determine version or exposure status, treat the instance as potentially vulnerable until verified.

How to remediate

The primary remediation is to apply the vendor-supplied update that addresses CVE-2023-22518. Follow Atlassian’s official instructions for upgrading Confluence Data Center or Server, including any required database or plugin compatibility steps. After patching, restart services and verify the new version string.

• Confirm the advisory’s list of fixed versions and any interim workarounds Atlassian published.
• Remove or restrict any temporary configuration changes once the patch is confirmed applied.
• Re-enable normal access controls and re-test that unauthenticated users can no longer reach the previously vulnerable functionality.
• Document the change and update vulnerability-management tickets so scanners and compliance tools reflect the remediated state.

CISA’s required action is to apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Prioritize internet-facing instances first.

If you can't patch immediately

When an immediate upgrade is not feasible, apply compensating controls to reduce the attack surface while planning the patch window.

• Segment Confluence behind a network firewall or zero-trust gateway so that only authenticated corporate networks or VPN users can reach it. Block direct internet access.
• Deploy or tune a web application firewall (WAF) or reverse-proxy rules that drop unauthenticated requests matching the patterns described in the vendor advisory. Treat this as virtual patching only; it is not a substitute for the official fix.
• If the advisory identifies a specific feature or endpoint that can be disabled without breaking critical workflows, turn that feature off until the patch is installed.
• Increase monitoring: alert on spikes in unauthenticated traffic to Confluence, unexpected content deletions, or administrative actions performed without corresponding login events. Retain logs for forensic review.
• If no effective mitigation exists and the instance cannot be isolated, consider temporarily taking the service offline or migrating critical content to a patched alternative, consistent with CISA guidance to discontinue use when mitigations are unavailable.

If your data may have been exposed

This vulnerability has been observed in ransomware campaigns. Although the flaw itself does not allow data exfiltration, ransomware operators often combine it with other techniques to encrypt or destroy data and demand payment. If you discover evidence of exploitation—missing pages, emptied spaces, or ransomware notes—activate your incident-response plan, preserve logs and snapshots, and engage forensic support.

Even when Confluence data itself was not stolen, attackers may have used the foothold for further movement. Review adjacent systems for compromise. As a quick personal check, you can run a free exposure scan of your email address against known breach data sets to see whether related credentials have appeared in other incidents.