CVE-2020-26214
📋 TL;DR
This vulnerability allows authentication bypass in Alerta monitoring systems configured with LDAP authentication. Attackers can gain unauthorized access by submitting empty passwords when LDAP servers permit unauthenticated bind requests. Only deployments with LDAP servers allowing anonymous authentication are affected.
💻 Affected Systems
- Alerta monitoring system
📦 What is this software?
Alerta by Alerta Project
Alerta by Alerta Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attackers gain administrative access to monitoring systems, potentially accessing sensitive infrastructure data and using Alerta as a pivot point to other systems.
Likely Case
Unauthorized access to monitoring dashboards, viewing of sensitive alert data, and potential privilege escalation within the Alerta platform.
If Mitigated
Authentication attempts with empty passwords are properly rejected with HTTP 401 responses, preventing unauthorized access.
🎯 Exploit Status
Exploitation is trivial - simply submit empty password field to LDAP authentication endpoint. Public GitHub references demonstrate the vulnerability and fix.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.1.0
Vendor Advisory: https://github.com/alerta/alerta/security/advisories/GHSA-5hmm-x8q8-w5jh
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Upgrade to Alerta version 8.1.0 or later using pip: 'pip install alerta-server>=8.1.0'. 3. Restart Alerta service. 4. Verify authentication rejects empty passwords.
🔧 Temporary Workarounds
LDAP Server Configuration
allConfigure LDAP servers to disallow unauthenticated bind requests for anonymous authorization.
# LDAP server specific configuration varies by implementation
# For OpenLDAP: set 'disallow bind_anon' in slapd.conf
# For Active Directory: configure 'LDAP server signing requirements'
🧯 If You Can't Patch
- Implement network-level controls to restrict access to Alerta endpoints only to authorized users/systems
- Deploy web application firewall (WAF) rules to block authentication attempts with empty password fields
🔍 How to Verify
Check if Vulnerable:
Attempt LDAP authentication with empty password field. If authentication succeeds, system is vulnerable.Check Version:
python -c "import alerta; print(alerta.__version__)" or check package manager: pip show alerta-serverVerify Fix Applied:
After patching, attempt LDAP authentication with empty password. Should receive HTTP 401 Unauthorized response.📡 Detection & Monitoring
Log Indicators:
- Authentication attempts with empty password fields
- Successful logins from unexpected sources
- Multiple failed authentication attempts followed by success with empty password
Network Indicators:
- HTTP POST requests to authentication endpoints with empty password parameters
- Unusual authentication patterns from single IPs
SIEM Query:
source="alerta.log" AND (message="authentication" AND password="") OR (status=200 AND uri="/auth/login" AND password="")🔗 References
- https://github.com/alerta/alerta/commit/2bfa31779a4c9df2fa68fa4d0c5c909698c5ef65
- https://github.com/alerta/alerta/issues/1277
- https://github.com/alerta/alerta/pull/1345
- https://github.com/alerta/alerta/security/advisories/GHSA-5hmm-x8q8-w5jh
- https://pypi.org/project/alerta-server/8.1.0/
- https://tools.ietf.org/html/rfc4513#section-5.1.2
- https://github.com/alerta/alerta/commit/2bfa31779a4c9df2fa68fa4d0c5c909698c5ef65
- https://github.com/alerta/alerta/issues/1277
- https://github.com/alerta/alerta/pull/1345
- https://github.com/alerta/alerta/security/advisories/GHSA-5hmm-x8q8-w5jh
- https://pypi.org/project/alerta-server/8.1.0/
- https://tools.ietf.org/html/rfc4513#section-5.1.2
