CVE-2023-29193

SpiceDB is an open source, Google Zanzibar-inspired, database system for creating and managing security-critical application permissions. The spicedb serve command contains a flag named --grpc-preshared-key which is used to protect the gRPC API from being accessed by unauthorized requests. The values of this flag are to be considered sensitive, secret data. The /debug/pprof/cmdline endpoint served by the metrics service (defaulting running on port 9090) reveals the command-line flags provided for debugging purposes. If a password is set via the --grpc-preshared-key then the key is revealed by this endpoint along with any other flags provided to the SpiceDB binary. This issue has been fixed in version 1.19.1.

Impact

All deployments abiding by the recommended best practices for production usage are NOT affected:

• Authzeds SpiceDB Serverless
• Authzeds SpiceDB Dedicated
• SpiceDB Operator

Users configuring SpiceDB via environment variables are NOT affected.

Users MAY be affected if they expose their metrics port to an untrusted network and are configuring --grpc-preshared-key via command-line flag.

Patches

TODO

Workarounds

To workaround this issue you can do one of the following:

• Configure the preshared key via an environment variable (e.g. SPICEDB_GRPC_PRESHARED_KEY=yoursecret spicedb serve)
• Reconfigure the --metrics-addr flag to bind to a trusted network (e.g. --metrics-addr=localhost:9090)
• Disable the metrics service via the flag (e.g. --metrics-enabled=false)
• Adopt one of the recommended deployment models: Authzeds managed services or the SpiceDB Operator

References

• GitHub Security Advisory issued for SpiceDB
• Go issue #22085 for documenting the risks of exposing pprof to the internet
• Go issue #42834 discusses preventing pprof registration to the default serve mux
• semgrep rule go.lang.security.audit.net.pprof.pprof-debug-exposure checks for a variation of this issue

Credit

Wed like to thank Amit Laish, a security researcher at GE Vernova for responsibly disclosing this vulnerability.

Weakness

The product generates an error message that includes sensitive information about its environment, users, or associated data.

Affected Software

Potential Mitigations

• Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
• If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
• Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/215.html
• https://cwe.mitre.org/data/definitions/463.html
• https://cwe.mitre.org/data/definitions/54.html
• https://cwe.mitre.org/data/definitions/7.html

References

• https://github.com/authzed/spicedb/commit/9bbd7d76b6eaba33fe0236014f9b175d21232999
• https://github.com/authzed/spicedb/releases/tag/v1.19.1
• https://github.com/authzed/spicedb/security/advisories/GHSA-cjr9-mr35-7xh6
• https://github.com/authzed/spicedb/commit/9bbd7d76b6eaba33fe0236014f9b175d21232999
• https://github.com/authzed/spicedb/releases/tag/v1.19.1
• https://github.com/authzed/spicedb/security/advisories/GHSA-cjr9-mr35-7xh6