This is a cross-post of the official security advisory. The official post contains a signed version with our PGP key, as well.

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The Rust Security Response Working Group was recently notified of a security issue affecting token generation in the crates.io web application, and while investigated that issue we discovered an additional vulnerability affecting crates.io API tokens.

We have no evidence of this being exploited in the wild, but out of an abundance of caution we opted to revoke all existing API keys. You can generate a new one at crates.io/me.

Overview

Until recently, API keys for crates.io were generated using the PostgreSQL random function, which is not a cryptographically secure random number generator. This means that in theory, an attacker could observe enough random values to determine the internal state of the random number generator, and use this information to determine previously created API keys up to the last database server reboot.

As part of the investigation for this, we also found that API keys were being stored in plain text. This would mean if our database were somehow compromised the attacker would be have API access for all current tokens.

Mitigations

We deployed a code change to production to use a cryptographically secure random number generator, and we implemented hashing for storing tokens in the database.

Exploiting either issue would be incredibly impractical in practice, and we've found no evidence of this being exploited in the wild. However, out of an abundance of caution, we've opted to revoke all existing API keys. You can generate a new API key by visiting crates.io/me. We apologize for any inconvenience this causes.

Acknowledgements

Thanks to Jacob Hoffman-Andrews for responsibly disclosing the random number generator issue according to our security policy. Thanks to Si^an Griffin and Justin Geibel from the crates.io team for helping the Security Response WG addressing both of the issues. Thanks to Pietro Albini from the Security Response WG for coordinating the work on this vulnerability.

Timeline of events

All times are listed in UTC.

• 2020-07-11 17:43 - The issue is reported to security@rust-lang.org
• 2020-07-11 20:56 - The issue is acknowledged, the leads of the crates.io team are looped in
• 2020-07-11 23:48 - The issue is confirmed and a planned fix is agreed on
• 2020-07-13 08:00 - The development of the fix is started
• 2020-07-14 12:53 - The fix is tested on the staging environment
• 2020-07-14 19:03 - The fix is deployed, existing tokens are revoked, and the issue is disclosed publicly

https://blog.rust-lang.org/2020/07/14/crates-io-security-advisory.html