CVE-2024-23656: Dex 2.37.0 is discarding TLSconfig and always serves deprecated TLS 1.0/1.1 and insecure ciphers

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-01-25 · updated 2026-06-17
Weakness: CWE-326

Description

Dex is an identity service that uses OpenID Connect to drive authentication for other apps. Dex 2.37.0 serves HTTPS with insecure TLS 1.0 and TLS 1.1. `cmd/dex/serve.go` line 425 seemingly sets TLS 1.2 as minimum version, but the whole `tlsConfig` is ignored after `TLS cert reloader` was introduced in v2.37.0. Configured cipher suites are not respected either. This issue is fixed in Dex 2.38.0.

Affected products

dexidp dex: 2.37.0

References

https://github.com/dexidp/dex/blob/70d7a2c7c1bb2646b1a540e49616cbc39622fb83/cmd/dex/serve.go#L425
https://github.com/dexidp/dex/commit/5bbdb4420254ba73b9c4df4775fe7bdacf233b17
https://github.com/dexidp/dex/issues/2848
https://github.com/dexidp/dex/pull/2964
https://github.com/dexidp/dex/security/advisories/GHSA-gr79-9v6v-gc9r
https://github.com/dexidp/dex/blob/70d7a2c7c1bb2646b1a540e49616cbc39622fb83/cmd/dex/serve.go#L425
https://github.com/dexidp/dex/commit/5bbdb4420254ba73b9c4df4775fe7bdacf233b17
https://github.com/dexidp/dex/issues/2848
https://github.com/dexidp/dex/pull/2964
https://github.com/dexidp/dex/security/advisories/GHSA-gr79-9v6v-gc9r

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