CVE-2021-3127 nats-io/jwt not enforcing checking of Import token permissions
Attackers can bypass access controls in NATS Server due to mishandled Import Token bindings, potentially gaining unauthorized access to resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-3127?
CVE-2021-3127 is a high-severity missing authorization vulnerability in n/a, published on 16 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
NATS Server 2.x before 2.2.0 and JWT library before 2.0.1 have Incorrect Access Control because Import Token bindings are mishandled.
Weakness: CWE-755
Which versions are affected by CVE-2021-3127?
15 open source packages ship an affected version, including github.com/nats-io/jwt, nats and github.com/nats-io/jwt/v2. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
github.com/nats-io/jwt Go | All versions to 1.2.2 | None |
github.com/nats-io/jwt Go | All versions to 1.2.2 | None |
github.com/nats-io/jwt Go | All versions | 1.2.3-0.20210314221642-a826c77dc9d2 |
github.com/nats-io/jwt Go | All versions | 1.2.3-0.20210314221642-a826c77dc9d2 |
github.com/nats-io/jwt Go | All versions | 1.2.3-0.20210314221642-a826c77dc9d2 |
nats Bitnami | From 2.0.0 | 2.2.0 |
9 more packages
github.com/nats-io/jwt/v2 Go | All versions | 2.0.1 |
github.com/nats-io/jwt/v2 Go | All versions | 2.0.1 |
github.com/nats-io/jwt/v2 Go | All versions | 2.0.1 |
github.com/nats-io/jwt/v2 Go | All versions | 2.0.1 |
github.com/nats-io/jwt/v2 Go | All versions | 2.0.1 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
Products include Linuxfoundation Nats-Server, Nats Jwt Library.
How do I fix CVE-2021-3127?
Upgrade github.com/nats-io/jwt to 1.2.3-0.20210314221642-a826c77dc9d2 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-3127 being exploited?
There is no known exploitation of CVE-2021-3127 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2022-28357 NATS nats-server allows directory traversal via unintended path to a management action
- CVE-2026-58253 NATS Server: Route API Auth Bypass
- CVE-2022-24450 Incorrect Authorization in NATS nats-server
- CVE-2026-33216 NATS has MQTT plaintext password disclosure
- CVE-2026-58207 NATS Server: Remote crash via integer overflow in Connz pagination
Sources
Also known as BIT-nats-2021-3127, DEBIAN-CVE-2021-3127, GHSA-62mh-w5cv-p88c, GHSA-9r5x-fjv3-q6h4, GHSA-j756-f273-xhp4, GO-2022-0386 and 1 more.