Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 99.2%; technical severity is CVSS 9.8.
Atlassian has been made aware of an issue reported by a handful of customers where external attackers may have exploited a previously unknown vulnerability in publicly accessible Confluence Data Center and Server instances to create unauthorized Confluence administrator accounts and access Confluence instances. Atlassian Cloud sites are not affected by this vulnerability. If your Confluence site is accessed via an atlassian.net domain, it is hosted by Atlassian and is not vulnerable to this issue.
Who should care
- Teams operating Confluence Data Center, Confluence Data Center and Server, Confluence Server
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Confluence Data Center, Confluence Data Center and Server, Confluence Server is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Check all affected Confluence instances for evidence of compromise per vendor instructions and report any positive findings to CISA.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Vendor remediation
Patch and remediation links
Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-20
- Affected versions
- Atlassian Confluence Data Center (Start Including: 8.5.0, End Excluding: 8.5.2); Atlassian Confluence Data Center and Server; Atlassian Confluence Server (Start Including: 8.5.0, End Excluding: 8.5.2)
- Published
- 4 October 2023
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- Added to CISA KEV
- Latest EPSS score: 99.2%
- Signal calculated at 88