attack-surface.md

Attack Surface Analysis for valkey-io/valkey

Attack Surface: Network Exposure of Valkey Instance

• Description: Valkey instance is directly accessible from untrusted networks, allowing potential attackers to attempt connections and exploits targeting Valkey itself.
• Valkey Contribution: Valkey, by design, listens on a network port and, if not properly secured, can be exposed to public or untrusted networks. Default port and lack of enforced TLS by default contribute to this exposure.
• Example: A Valkey instance deployed on a cloud server with the default port 6379 open to the internet and no firewall restrictions. Attackers can easily discover this open port and attempt to connect and exploit potential Valkey vulnerabilities or misconfigurations.
• Impact: Unauthorized access to Valkey data, potential data breaches, data manipulation, denial of service, and in severe cases, potential compromise of the underlying server if Valkey vulnerabilities are exploited.
• Risk Severity: High
• Mitigation Strategies:
  • Network Segmentation: Deploy Valkey within a private network or subnet, isolating it from direct internet access.
  • Firewall Rules: Configure strict firewall rules to restrict access to Valkey ports (default 6379, or custom port) only from trusted sources like application servers.
  • Mandatory TLS/SSL Encryption: Enforce TLS/SSL encryption for all client-server communication by configuring tls-port and disabling the non-TLS port (port 0). This protects data in transit from eavesdropping and MitM attacks.
  • Non-Default Port: Change the default Valkey port to a non-standard, less predictable port to reduce automated scanning and discovery attempts.

Attack Surface: Weak or Missing Authentication

• Description: Valkey instance operates without strong authentication or with easily bypassed authentication mechanisms, allowing unauthorized access and command execution.
• Valkey Contribution: Valkey's default configuration does not enforce authentication. If requirepass or ACLs are not properly configured, any network-accessible client can connect and interact with Valkey without credentials.
• Example: A Valkey instance running with default configuration (no requirepass set). An attacker who gains network access to the Valkey port can connect and execute any Valkey command, including administrative commands like CONFIG GET, FLUSHALL, or SHUTDOWN.
• Impact: Complete unauthorized access to all data stored in Valkey, full data manipulation and deletion capabilities, denial of service, potential for data breaches and significant operational disruption.
• Risk Severity: Critical
• Mitigation Strategies:
  • Mandatory Authentication: Always enable strong authentication by configuring requirepass in valkey.conf with a strong, randomly generated password.
  • Implement ACL (Access Control List): Utilize Valkey's ACL system to define granular permissions for different users and applications. Restrict access based on the principle of least privilege, limiting users to only the commands and keyspaces they need.
  • Regular Password Rotation: Implement a policy for regular rotation of the requirepass and ACL user passwords.

Attack Surface: Abuse of Powerful Valkey Commands

• Description: Even with authentication, attackers who gain access (or internal malicious actors) can abuse inherently powerful Valkey commands to cause significant harm.
• Valkey Contribution: Valkey includes powerful commands like EVAL (Lua scripting), MODULE LOAD, CONFIG, DEBUG, and administrative commands. Unrestricted access to these commands, even with basic authentication, presents a significant risk.
• Example: An attacker with valid (but perhaps compromised or misused) Valkey credentials uses the EVAL command to execute a Lua script that exfiltrates sensitive data, performs a denial of service, or attempts to interact with the underlying server. Or, abuse of CONFIG SET to weaken security settings.
• Impact: Data breaches, data manipulation, denial of service, potential server compromise depending on the abused command and the attacker's skill.
• Risk Severity: High
• Mitigation Strategies:
  • Restrict Access to Powerful Commands via ACL: Utilize Valkey ACLs to strictly control access to powerful and potentially dangerous commands. Deny access to commands like EVAL, MODULE, CONFIG, DEBUG, SCRIPT, CLUSTER, REPLICAOF/SLAVEOF, SHUTDOWN for most users and applications, granting access only to highly privileged roles when absolutely necessary.
  • Disable Unnecessary Features: If Lua scripting or modules are not required for your application, disable them in the Valkey configuration to reduce the attack surface and eliminate the risk of their abuse.
  • Regular Auditing of ACLs and Command Usage: Regularly audit Valkey ACL configurations and monitor command usage patterns to detect and respond to any suspicious or unauthorized use of powerful commands.

Attack Surface: Denial of Service (DoS) through Valkey Resource Exhaustion

• Description: Attackers exploit Valkey's resource management limitations or vulnerabilities to cause denial of service by exhausting server resources (CPU, memory, connections).
• Valkey Contribution: Valkey, like any database, can be vulnerable to resource exhaustion if not properly configured. Inefficient commands, large data operations, and lack of resource limits can be exploited for DoS.
• Example: An attacker floods Valkey with commands that create extremely large data structures (e.g., very long strings or huge lists), rapidly consuming server memory and leading to out-of-memory errors and service disruption. Or, sending a high volume of CPU-intensive commands like SORT on large datasets.
• Impact: Service disruption, application downtime, data unavailability, impacting business operations and user experience.
• Risk Severity: High
• Mitigation Strategies:
  • Configure Resource Limits: Utilize Valkey's configuration options to set appropriate resource limits, such as maxmemory to limit memory usage, maxclients to limit concurrent connections, and potentially configure limits on specific command execution times or resource consumption (if available through modules or external tools).
  • Implement Rate Limiting: Implement rate limiting at the application or network level to restrict the number of requests from a single source within a given time frame, preventing flood-based DoS attacks.
  • Monitor Valkey Resource Usage and Performance: Continuously monitor Valkey's CPU, memory, and connection usage, as well as command execution performance, to detect and respond to potential DoS attacks or performance degradation. Set up alerts for unusual resource consumption patterns.
  • Optimize Data Structures and Commands: Design your application to use Valkey data structures and commands efficiently, avoiding operations that are known to be resource-intensive, especially with large datasets.

Attack Surface: Valkey Specific Bugs and Vulnerabilities

• Description: Valkey, being a fork of Redis, may contain unique bugs and vulnerabilities introduced during its development or inherited from Redis but not yet addressed in Valkey.
• Valkey Contribution: As a separate project, Valkey has its own codebase and development lifecycle, which can lead to the introduction of new vulnerabilities or delayed patching of existing ones compared to upstream Redis.
• Example: A buffer overflow vulnerability discovered in Valkey's specific implementation of a command parsing routine, which could be exploited for remote code execution. Or, a vulnerability in a Valkey-specific feature or module.
• Impact: Varies widely depending on the nature of the vulnerability, ranging from denial of service and data corruption to remote code execution and complete server compromise.
• Risk Severity: Varies, can be Critical depending on the specific vulnerability.
• Mitigation Strategies:
  • Prioritize Regular Valkey Updates: Establish a process for promptly updating Valkey to the latest stable version as soon as security patches and updates are released. Subscribe to Valkey's security advisories and release notes.
  • Security Monitoring and Vulnerability Scanning: Implement security monitoring and vulnerability scanning for your Valkey instances to proactively identify and address potential vulnerabilities.
  • Follow Valkey Security Best Practices and Hardening Guides: Adhere to security recommendations and hardening guides provided by the Valkey project and security community.
  • Participate in Valkey Security Community: Engage with the Valkey security community, report any discovered vulnerabilities responsibly, and stay informed about security discussions and advisories.