GitHub Advisoryadvisory · Go
GHSA-4w5x-x539-ppf5 Incorrect handling of credential expiry by /nats-io/nats-server
CRITICAL
Official page ↗
- Aliases
- CVE-2020-26892
- Ecosystem
- Go
- Packages
- github.com/nats-io/jwt
- Severity
- Critical
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-798
- Reviewed
- 2021-05-21
Affected packages
• Go github.com/nats-io/jwt: < 1.1.0 → fixed in 1.1.0
Description
Problem Description
NATS nats-server through 2020-10-07 has Incorrect Access Control because of how expired credentials are handled.
The NATS accounts system has expiration timestamps on credentials; the library had an API which encouraged misuse and an `IsRevoked()` method which misused its own API.
A new `IsClaimRevoked()` method has correct handling and the nats-server has been updated to use this. The old `IsRevoked()` method now always returns true and other client code will have to be updated to avoid calling it.
The CVE identifier should cover any application using the old JWT API, where the nats-server is one of those applications.
Affected versions
JWT library
• all versions prior to 1.1.0
• fixed after nats-io/jwt PR 103 landed (2020-10-06)
NATS Server
• Version 2 prior to 2.1.9
+ 2.0.0 through and including 2.1.8 are vulnerable.
• fixed with nats-io/nats-server PRs 1632, 1635, 1645
Impact
Time-based credential expiry did not work.
Workaround
Have credentials which only expire after fixes can be deployed.
Solution
Upgrade the JWT dependency in any application using it.
Upgrade the NATS server if using NATS Accounts.
Related
Alias · CVE (1)
- CVE-2020-26892 The JWT library in NATS nats-server before 2.1.9 has Incorrect Access Control because of how expired credentials are handled. vulnerability
Weakness · CWE (1)
- CWE-798 Use of Hard-coded Credentials weakness
References
- https://github.com/nats-io/jwt/security/advisories/GHSA-4w5x-x539-ppf5 web
- https://nvd.nist.gov/vuln/detail/CVE-2020-26892 advisory
- https://github.com/nats-io/jwt/commit/e11ce317263cef69619fc1ca743b195d02aa1d8a web
- https://github.com/nats-io/nats-server/commit/1e08b67f08e18cd844dce833a265aaa72500a12f web
- https://advisories.nats.io/CVE/CVE-2020-26892.txt web
- https://github.com/nats-io/jwt package
- https://github.com/nats-io/nats-server/commits/master web
- https://lists.fedoraproject.org/archives/list/[email protected]/message/VT67XCLIIBYRT762SVFBYFFTQFVSM3SI web
- https://pkg.go.dev/vuln/GO-2022-0380 web
- https://www.openwall.com/lists/oss-security/2020/11/02/2 web