CVE-2022-37026 Overview
CVE-2022-37026 is a critical authentication bypass vulnerability affecting Erlang/OTP's SSL, TLS, and DTLS implementations. The vulnerability allows attackers to bypass client certificate authentication in certain client-certification situations, potentially enabling unauthorized access to systems that rely on certificate-based authentication for security.
Critical Impact
This authentication bypass vulnerability allows attackers to circumvent client certificate verification in SSL/TLS/DTLS connections, potentially gaining unauthorized access to protected resources without valid credentials.
Affected Products
- Erlang/OTP versions before 23.3.4.15
- Erlang/OTP versions 24.x before 24.3.4.2
- Erlang/OTP versions 25.x before 25.0.2
Discovery Timeline
- September 21, 2022 - CVE-2022-37026 published to NVD
- May 27, 2025 - Last updated in NVD database
Technical Details for CVE-2022-37026
Vulnerability Analysis
This vulnerability resides in Erlang/OTP's implementation of client certificate authentication for secure communication protocols including SSL, TLS, and DTLS. When client certificate verification is enabled on a server, the implementation fails to properly validate client certificates under certain conditions, allowing an attacker to establish a connection without presenting valid credentials.
The authentication bypass affects applications that rely on mutual TLS (mTLS) authentication, where both the server and client must present valid certificates to establish a secure connection. This is a common pattern for securing microservices communication, API endpoints, and enterprise applications built on the Erlang/OTP platform.
Erlang/OTP is widely used in telecommunications, messaging platforms, and distributed systems. Products built on Erlang, such as RabbitMQ, CouchDB, and various telecommunications infrastructure, may be affected if they utilize client certificate authentication.
Root Cause
The root cause lies in improper validation logic within Erlang/OTP's SSL/TLS/DTLS handler during the client certificate verification phase. Under specific client-certification scenarios, the verification process can be bypassed, allowing connections to proceed without proper authentication of the client's identity. The exact implementation flaw allows certain malformed or missing certificate chains to pass validation checks that should otherwise reject the connection.
Attack Vector
The vulnerability is exploitable over the network without requiring any privileges or user interaction. An attacker targeting a system that uses Erlang/OTP's SSL/TLS/DTLS with client certificate authentication can craft malicious connection requests that bypass the certificate verification process.
The attack scenario involves:
- Identifying a target system using Erlang/OTP with client certificate authentication enabled
- Initiating a TLS/DTLS connection to the target service
- Exploiting the verification bypass during the certificate exchange phase
- Gaining unauthorized access to the protected service
Since no proof-of-concept code is publicly available, the specific exploitation technique details are not published. For technical details, refer to the GitHub OTP Version Comparison which shows the changes made between vulnerable and patched versions.
Detection Methods for CVE-2022-37026
Indicators of Compromise
- Unexpected successful TLS/SSL connections from clients without valid certificates in authentication logs
- Anomalous connection patterns to services requiring mutual TLS authentication
- Authentication events showing bypass or missing certificate validation steps
- Connections from unknown or unauthorized sources to certificate-protected endpoints
Detection Strategies
- Monitor SSL/TLS handshake events for connections that complete successfully without valid client certificate presentation
- Implement network traffic analysis to detect anomalous connection patterns to mTLS-protected services
- Review application logs for authentication events that indicate certificate verification was bypassed
- Deploy intrusion detection rules to flag suspicious TLS negotiation behavior
Monitoring Recommendations
- Enable verbose logging for Erlang/OTP SSL applications to capture certificate verification events
- Implement real-time alerting for authentication anomalies on services using client certificates
- Monitor connection metadata to identify clients connecting without expected certificate attributes
- Conduct periodic audits of successful connections against expected client certificate inventory
How to Mitigate CVE-2022-37026
Immediate Actions Required
- Upgrade Erlang/OTP to version 23.3.4.15 or later for the 23.x branch
- Upgrade Erlang/OTP to version 24.3.4.2 or later for the 24.x branch
- Upgrade Erlang/OTP to version 25.0.2 or later for the 25.x branch
- Audit all services using Erlang/OTP SSL/TLS/DTLS with client certificate authentication
- Review connection logs for any evidence of exploitation prior to patching
Patch Information
Erlang has released patched versions that address this authentication bypass vulnerability. The fixes are available in:
- Erlang/OTP 23.3.4.15 - View changes on GitHub
- Erlang/OTP 24.3.4.2
- Erlang/OTP 25.0.2
Additional information is available in the Erlang Forums Announcements and the OTP 25.1 Release Notes. Debian users should refer to the Debian LTS Announcement for distribution-specific guidance.
Workarounds
- Consider disabling client certificate authentication temporarily if patching is not immediately possible
- Implement additional network-layer access controls to restrict which clients can reach affected services
- Deploy a reverse proxy or TLS termination layer with separate certificate validation
- Monitor and audit all connections to affected services until patches can be applied
# Verify installed Erlang/OTP version
erl -eval 'erlang:display(erlang:system_info(otp_release)), halt().' -noshell
# Check for vulnerable versions (output should be 23.3.4.15+, 24.3.4.2+, or 25.0.2+)
# Upgrade using your package manager or from source:
# For source installation, download from erlang.org/downloads
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
