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HOME/INTELLIGENCE/Critical Advisory: CVE-2023-22518 Atlassian Confluence Improper Authorization Vulnerability
CVE-2023-22518
11/7/2023
CVSS 9.3 • CRITICAL

Critical Advisory: CVE-2023-22518 Atlassian Confluence Improper Authorization Vulnerability

Atlassian Confluence Data Center and Server contain an improper authorization vulnerability that can result in significant data loss when exploited by an unauthenticated attacker. There is no impact on confidentiality since the attacker cannot exfiltrate any data.

FREQUENTLY ASKED

What is CVE-2023-22518 and why is it considered critical?

CVE-2023-22518 is an Improper Authorization vulnerability (CWE-863) in Atlassian Confluence Data Center and Server with a CVSS score of 10.0. It is critical because it allows an unauthenticated remote attacker to reset the Confluence instance and create a new administrator account, granting them total control over the environment, which can lead to complete data loss and system unavailability.

Which versions of Confluence Data Center and Server are affected?

All versions of Confluence Data Center and Server are affected by CVE-2023-22518. Specifically, fixed versions include those starting from 7.19.16, 8.3.4, 8.4.4, 8.5.3, and 8.6.1. If you are running any version below these specified releases, your instance is considered vulnerable and requires immediate remediation to prevent unauthorized administrative access.

Has a patch been released for CVE-2023-22518?

Yes, Atlassian has released patches for CVE-2023-22518. Administrators should upgrade their Confluence Data Center and Server instances to the following versions or higher: 7.19.16, 8.3.4, 8.4.4, 8.5.3, or 8.6.1. Applying these updates is the primary method to resolve the improper authorization flaw and secure the instance against unauthenticated administrator account creation.

What is the remediation deadline for CVE-2023-22518?

The remediation deadline for CVE-2023-22518 is 2023-11-28. For many organizations, particularly those following CISA guidelines, this deadline marks the required date for applying updates to maintain regulatory compliance. Missing this deadline increases the risk of exploitation, especially given that active ransomware use has been associated with this specific vulnerability.

How can I check if my Confluence deployment is affected by CVE-2023-22518?

To check if your deployment is affected, verify the version number of your Confluence Data Center or Server instance. If the version is older than 7.19.16, 8.3.4, 8.4.4, 8.5.3, or 8.6.1, your deployment is vulnerable. Additionally, check for unusual administrative account creations or unauthorized system resets, as these are primary indicators of exploitation in an unpatched environment.

THREAT SURVEY

VULNERABILITY TARGET

Confluence Data Center and Server

VENDOR SOURCE

Atlassian

CLASSIFIERS

CWE-863

REMEDIATION PULSE

Critical patching mandated by November 28, 2023.

EXPLOITATION STATUS: ACTIVE_WILDFIRE

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Executive Summary

CVE-2023-22518 represents a maximum-severity security flaw within Atlassian Confluence Data Center and Server environments. Classified as an Improper Authorization vulnerability (CWE-863), this defect carries a CVSS score of 10.0, indicating the highest possible level of risk. The vulnerability allows an unauthenticated, remote attacker to trigger a system reset and subsequently establish a new instance administrator account. Once this foothold is established, the attacker gains unrestricted control over the Confluence instance, enabling them to manipulate data, delete content, and disrupt services. With active exploitation and known ransomware involvement, organizations must prioritize remediation before the 2023-11-28 deadline to ensure operational continuity and compliance.

Vulnerability Profile

FieldValue
CVE IDCVE-2023-22518
Affected Product & VersionsConfluence Data Center and Server: All versions < 7.19.16, 8.3.4, 8.4.4, 8.5.3, 8.6.1
CVSS Score & Severity10.0 (CRITICAL)
CVSS Version3.0
CVSS VectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
CWE IDsCWE-863 (Incorrect Authorization)
Date Disclosed2023-11-07
Remediation Deadline2023-11-28
SSVC Exploitation statusActive
Known Ransomware UseYes
EPSS Score & Percentile0.94375 (100.0%)
Patch AvailableYes

Technical Deep Dive: Understanding CWE-863 in Confluence

At the core of CVE-2023-22518 is a failure in the authorization logic of Confluence's setup and configuration modules. CWE-863, or Incorrect Authorization, occurs when a software application performs an authorization check but does so incorrectly, allowing users to access resources or perform actions that should be restricted. In the context of Confluence, the vulnerability manifests in how the application manages its "setup mode" and restoration endpoints.

The Attack Chain

The vulnerability is particularly dangerous because it does not require valid credentials or sophisticated exploitation techniques. An attacker targets specific endpoints responsible for system restoration or initial configuration. Under normal circumstances, these endpoints should only be accessible if the system is in an unconfigured state or if the requester provides valid high-level administrative credentials. However, due to the improper authorization flaw, an unauthenticated network-based attacker can bypass these checks.

  1. System Reset Trigger: The attacker sends a crafted request to a vulnerable endpoint, effectively tricking the application into believing it needs to undergo a setup or restoration process. This action can lead to the clearing of existing configuration data or the initialization of a fresh administrative setup phase.
  2. Admin Account Creation: Once the instance is forced into this state, the attacker accesses the setup wizard. Because the application now considers itself to be in an "unconfigured" state, it allows the creation of a new, initial administrator account without requiring any prior authentication.
  3. Full Compromise: With a newly minted administrative account, the attacker gains the highest level of privilege within the Confluence instance. They can modify system settings, access all spaces, delete content, or install malicious plugins to maintain persistence or pivot further into the internal network.

Attack Surface and Blast Radius

The attack surface includes any Confluence Data Center or Server instance exposed to the internet or an untrusted local network. The blast radius is catastrophic; while the source data indicates no impact on confidentiality regarding data exfiltration, the impact on integrity and availability is absolute. This vulnerability is a prime target for ransomware actors who seek to encrypt or delete enterprise knowledge bases to extort organizations.

Who Is Affected: Impacts and Compliance

This vulnerability impacts all organizations utilizing self-hosted Atlassian Confluence Data Center or Server deployments. This includes a wide range of sectors from technology and finance to government and healthcare. Importantly, Atlassian Cloud sites (those hosted at atlassian.net) are not affected by this specific flaw.

Compliance and Legal Urgency

The Cybersecurity and Infrastructure Security Agency (CISA) has recognized the severity of this issue, and the remediation deadline of 2023-11-28 aligns with mandates like Binding Operational Directive (BOD) 22-01. Federal agencies and regulated industries are required to patch known exploited vulnerabilities within specific timeframes. Failure to remediate by this date not only leaves the organization exposed to ransomware but also constitutes a failure in regulatory compliance, potentially leading to legal and financial repercussions.

Official Remediation Steps

To mitigate the risk posed by CVE-2023-22518, administrators must immediately upgrade their Confluence instances to a fixed version. Atlassian has provided several updated release branches to facilitate a smooth transition for users on different long-term support (LTS) paths.

  1. Identify Current Version: Determine the version of Confluence currently in use by checking the System Information page in the Administration console.
  2. Select Fixed Version: Choose the appropriate upgrade path based on your current deployment:
    • If on 7.19.x, upgrade to 7.19.16 or higher.
    • If on 8.3.x, upgrade to 8.3.4 or higher.
    • If on 8.4.x, upgrade to 8.4.4 or higher.
    • If on 8.5.x, upgrade to 8.5.3 or higher.
    • If on 8.6.x, upgrade to 8.6.1 or higher.
  3. Apply Patch: Download the latest installer from the Atlassian Patch URL. Follow the standard upgrade procedure, ensuring a full backup is taken prior to the operation.
  4. Verify Integrity: After the upgrade, review the Confluence user directory for any unauthorized administrator accounts that may have been created prior to the patch application. Monitor system logs for access to /setup/* or /admin/* endpoints from unrecognized IP addresses.

Strategic Security Best Practices

Beyond patching, organizations should implement the following defensive measures to protect against improper authorization and remote exploitation of enterprise software:

  • Network Segmentation: Place Confluence instances behind a VPN or a Zero Trust Network Access (ZTNA) gateway. Restrict access to the management UI and configuration endpoints to specific, trusted IP ranges.
  • Implement Web Application Firewalls (WAF): Deploy WAF rules that specifically block access to setup and restoration endpoints from the public internet. Many WAF vendors provide virtual patching for CVE-2023-22518.
  • Least Privilege Principle: Ensure that the database user and filesystem service account running Confluence have the minimum permissions necessary to function. This limits the potential damage an attacker can do even if they gain application-level admin access.
  • Enhanced Monitoring and Alerting: Configure Security Information and Event Management (SIEM) alerts for unusual administrative actions, such as the creation of new users with "confluence-administrators" privileges or changes to the system configuration files.
  • Regular Backup Audits: Given the "reset" nature of this vulnerability, ensure that your backup and disaster recovery processes are robust. Regularly test restores to verify that data can be recovered quickly in the event of a ransomware-induced wipe.
  • Vulnerability Scanning: Use automated tools to scan your external and internal perimeters for unpatched Atlassian products, utilizing the high EPSS score (0.94375) as a justification for urgent remediation in risk management reports.