CriticalCVE-2023-22515

    Atlassian Confluence Data Center and Server Broken Access Control Vulnerability (CVE-2023-22515)

    Published In CISA KEV since Sources: SingCERT, pwn.watch, CVE.org

    What is affected, what to do

    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.

    The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. Update Atlassian Confluence Data Center to version 8.3.3, Atlassian Confluence Data Center to version 8.4.3, Atlassian Confluence Data Center to version 8.5.2. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Atlassian Confluence Data Center lt 8.0.0..8.3.3
    • Atlassian Confluence Data Center lt 8.4.0..8.4.3
    • Atlassian Confluence Data Center lt 8.5.0..8.5.2
    • Atlassian Confluence Server lt 8.0.0..8.3.3
    • Atlassian Confluence Server lt 8.4.0..8.4.3
    • Atlassian Confluence Server lt 8.5.0..8.5.2
    Fixed in
    • Atlassian Confluence Data Center 8.3.3
    • Atlassian Confluence Data Center 8.4.3
    • Atlassian Confluence Data Center 8.5.2
    • Atlassian Confluence Server 8.3.3
    • Atlassian Confluence Server 8.4.3
    • Atlassian Confluence Server 8.5.2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    10.0

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    10.0

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: SingCERT, pwn.watch, CVE.org

    99.22 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.93

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    258.46 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: CSA/SingCERT How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    10.0 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    10.0
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    99.22 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    99.93
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw is network-reachable without authentication or user interaction, and exploitation is trivial. A handful of HTTP requests yields a full administrator account. Attackers typically follow up with plugin-based code execution, persistence and data theft. CISA flags known ransomware campaign use, and exploitation likelihood sits among the very highest of any CVE. Organisations exposing Confluence as a knowledge base holding project, engineering or credential data are prime targets. Score any internet-facing instance in the affected range as critical, requiring immediate action plus a compromise assessment. Patch internal-only instances within days, as they are a favoured lateral-movement target once an attacker has a foothold.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Find and pull exposed instances off the internet now: Inventory every Confluence Data Center/Server instance running 8.0.x through 8.5.x. Put any internet-facing instance behind VPN or an IP allowlist until patched. This covers Tomcat on 8090 directly or via a reverse proxy on 443. Atlassian Cloud sites (*.atlassian.net) are not affected.
      • Patch: Upgrade to a fixed release, 8.3.3, 8.4.3 or 8.5.2 (or later). On Data Center clusters, upgrade every node. Releases prior to 8.0.0 are not affected per the advisory.
      • Stopgap if you can't patch today: Block all access to /setup/* at the reverse proxy or load balancer. These endpoints have no legitimate use on a running production instance.
      • Hunt for compromise before and after patching: Review confluence-administrators for unknown members and audit user accounts created since early September 2023. Also check installed apps/plugins for anything unfamiliar. Patching does not remove admin accounts an attacker has already created.
      • Escalate on any finding: Treat an instance with a rogue admin as fully compromised. Isolate the host and preserve evidence (logs, heap, DB dump). Rotate every credential reachable from Confluence, including service accounts, LDAP bind users, API tokens and secrets pasted into pages. Then rebuild from a known-good backup. Assess NIS2 reporting obligations, which require an early warning within 24 h.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Restrict Confluence to internal networks or ZTNA access only. Apply egress filtering on the Confluence host so it can reach only required destinations (Marketplace, LDAP, SMTP). This cuts off C2 traffic and tool staging.
      • WAF/reverse proxy rule: Drop requests to /setup/ and any query string containing bootstrapStatusProvider or applicationConfig.setupComplete. nginx example: location ~* ^/setup/ { deny all; }. Add a rule against parameter tampering on server-info.action.
      • IPS: Enable vendor signatures for CVE-2023-22515 on Suricata/Snort or your NGFW. If none are available, deploy a URI content match on setupComplete=false in blocking mode.
      • IAM/least privilege: Keep the admin role to a small set of named accounts. Enforce SSO with MFA for admin access and disable local admin accounts where feasible. Script a recurring group-membership review via the REST API.
      • Endpoint hardening: Run Confluence under a dedicated unprivileged service account. Use EDR policy to block, or at minimum alert on, shells (cmd.exe, powershell.exe, /bin/sh, bash) spawned by the JVM. Disallow unsigned plugin uploads.

    3. Runbook step 3

      Detection rules

      • Web/proxy access logs: Look for hits on /setup/setupadministrator.action, /setup/finishsetup.action, /setup/setupadministrator-start.action, or server-info.action?bootstrapStatusProvider.applicationConfig.setupComplete=false. SPL: index=web (uri_path="/setup/*" OR uri_query="*setupComplete*") host=confluence*
      • Confluence application logs: Search atlassian-confluence.log and atlassian-confluence-security.log for setup events, new admin users, and changes to confluence-administrators outside change windows. In the built-in audit log, review "User created" and "Added to group" events.
      • EDR/Sysmon process ancestry: Alert on Sysmon EID 1 or Windows Event ID 4688 where the parent is java.exe/tomcat*.exe and the child is a shell. KQL: DeviceProcessEvents | where InitiatingProcessFileName =~ "java.exe" and InitiatingProcessCommandLine has "confluence" and FileName in~ ("cmd.exe","powershell.exe","bash","sh"). On Linux, correlate auditd execve records against the ppid of the Confluence JVM.
      • File system: Use Sysmon EID 11 or an auditd watch for new JARs under <confluence-home>/plugins-* and for JSP/webshell artefacts in the install directory.
      • Network telemetry (Zeek/Suricata): Flag unusual outbound connections from the Confluence host in conn.log, especially to unknown IPs, tunnelling or file-sharing services. Treat large response volumes on export endpoints (/spaces/exportspace.action) as possible exfiltration.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    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.

    Source: CSA/SingCERT, pwn.watch, NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    AtlassianConfluence Data Center
    • 8.4.0 – < 8.4.3
    • 8.0.0 – < 8.3.3
    • 8.5.0 – < 8.5.2
    • 8.4.3
    • 8.3.3
    • 8.5.2
    AtlassianConfluence Server
    • 8.4.0 – < 8.4.3
    • 8.5.0 – < 8.5.2
    • 8.0.0 – < 8.3.3
    • 8.4.3
    • 8.5.2
    • 8.3.3
    atlassianconfluence_data_center
    • 8.4.0 – < 8.4.3
    • 8.0.0 – < 8.3.3
    • 8.5.0 – < 8.5.2
    • 8.4.3
    • 8.3.3
    • 8.5.2
    atlassianconfluence_server
    • 8.4.0 – < 8.4.3
    • 8.0.0 – < 8.3.3
    • 8.5.0 – < 8.5.2
    • 8.4.3
    • 8.3.3
    • 8.5.2

    Vendors and products

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    CSA/SingCERTActive Exploitation of Critical Vulnerability in Confluence Data Center and Server (opens in a new tab)CSA/SingCERTactively exploited
    Packet StormAtlassian Confluence Unauthenticated Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—

    References & sources

    • packetstormsecurity.comfiles/175225/Atlassian-Confluence-Unauthenticated-Remote-Code-E…Exploit, Third-party advisory, Vulnerability database
    • confluence.atlassian.comdisplay/KB/FAQ+for+CVE-2023-22515Vendor advisory
    • confluence.atlassian.compages/viewpage.action?pageId=1295682276Vendor advisory
    • jira.atlassian.combrowse/CONFSERVER-92475Issue tracking, Vendor advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2023-22515government-resource, US government resource
    • pwn.watchpwn.watch: Confluence Data Center/Server zero-day lets attackers create admins (CVE-2023-22515)pwn-watch
    • confluence.atlassian.comCVE-2023-22515 - Broken Access Control Vulnerability in Confluence Data Center and Serverpwn-watch
    • cisa.govThreat Actors Exploit Atlassian Confluence CVE-2023-22515 for Initial Access to Networks (AA23-289A)pwn-watch
    • NVD (NIST)NVD: CVE-2023-22515pwn-watch
    • cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch
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