CVE-2022-26562 – This authentication bypass vulnerability in Kop... (How to Fix)

Q: What is the severity of CVE-2022-26562?

CVE-2022-26562 has a CVSS score of 9.8 (CRITICAL). This authentication bypass vulnerability in Kopano Core and Zarafa Collaboration Platform allows attackers to authenticate with expired user accounts or passwords. It affects systems using Kerberos or PAM authentication modules. Organizations running vulnerable versions of these collaboration platforms are at risk.

📋 TL;DR

This authentication bypass vulnerability in Kopano Core and Zarafa Collaboration Platform allows attackers to authenticate with expired user accounts or passwords. It affects systems using Kerberos or PAM authentication modules. Organizations running vulnerable versions of these collaboration platforms are at risk.

💻 Affected Systems

Products:

Kopano Core
Zarafa Collaboration Platform

Versions: Kopano Core <= v11.0.2.51; Zarafa >= 6.30 (introduced between 6.30.0 RC1e and 6.30.8 final)

Operating Systems: Linux distributions running affected versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using Kerberos (Kopano) or PAM (Zarafa) authentication modules.

📦 What is this software?

Groupware Core by Kopano

View all CVEs affecting Groupware Core →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete compromise of the collaboration platform with unauthorized access to all user data, emails, and files, potentially leading to data exfiltration or ransomware deployment.

🟠

Likely Case

Unauthorized access to user accounts, email reading/sending, file access, and potential privilege escalation within the platform.

🟢

If Mitigated

Limited impact if strong network segmentation, monitoring, and additional authentication layers are in place.

🌐 Internet-Facing: HIGH

🏢 Internal Only: HIGH

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires valid user credentials but bypasses account/password expiration checks.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kopano Core > v11.0.2.51; specific Zarafa patches for affected versions

Vendor Advisory: https://jira.kopano.io/browse/KC-2021

Restart Required: Yes

Instructions:

1. Update Kopano Core to version >11.0.2.51 or apply Zarafa patches. 2. Restart Kopano/Zarafa services. 3. Verify authentication works correctly with expired accounts.

🔧 Temporary Workarounds

Disable Kerberos/PAM Authentication

linux

Temporarily switch to alternative authentication methods until patching is complete

# Edit Kopano/Zarafa configuration to use non-Kerberos/PAM auth
# Restart services after configuration change

🧯 If You Can't Patch

Implement network segmentation to isolate vulnerable systems from critical infrastructure
Enable detailed authentication logging and monitor for suspicious login attempts with expired accounts

🔍 How to Verify

Check if Vulnerable:

Check Kopano Core version with 'kopano-server --version' or Zarafa version via package manager. Verify if using Kerberos/PAM authentication.

Check Version:

kopano-server --version 2>/dev/null || dpkg -l | grep -i kopano || rpm -qa | grep -i kopano

Verify Fix Applied:

Test authentication with an expired user account - it should be rejected after patching.

📡 Detection & Monitoring

Log Indicators:

Successful authentication events for expired user accounts
Kerberos/PAM authentication failures followed by successes

Network Indicators:

Authentication traffic to Kopano/Zarafa services from unexpected sources

SIEM Query:

source="kopano.log" OR source="zarafa.log" AND (event="authentication success" AND user_status="expired")

📊 Metadata

CVE ID: CVE-2022-26562

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-287

Published: April 1, 2022

Last Updated: November 21, 2024

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2022-26562, you might also want to check these: