CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
25.8%
Dex 2.37.0 is serving HTTPS with insecure TLS 1.0 and TLS 1.1.
While working on https://github.com/dexidp/dex/issues/2848 and implementing configurable TLS support, I noticed my changes did not have any effect in TLS config, so I started investigating.
https://github.com/dexidp/dex/blob/70d7a2c7c1bb2646b1a540e49616cbc39622fb83/cmd/dex/serve.go#L425 is seemingly setting TLS 1.2 as minimum version, but the whole tlsConfig is ignored after “TLS cert reloader” was introduced in https://github.com/dexidp/dex/pull/2964. Configured cipher suites are not respected either, as seen on the output.
Build Dex, generate certs with gencert.sh
, modify config.dev.yaml
to run on https, using generated certs.
issuer: http://127.0.0.1:5556/dex
storage:
type: sqlite3
config:
file: dex.db
web:
https: 127.0.0.1:5556
tlsCert: examples/k8s/ssl/cert.pem
tlsKey: examples/k8s/ssl/key.pem
<rest as default>
Run dex bin/dex serve config.dev.yaml
.
Install sslyze
, easy to use SSL connection analyzer:
pip3 install sslyze
sslyze 127.0.0.1:5556
In Dex 2.37.0, TLS 1.0 and TLS 1.1 are enabled in addition to expected TLS 1.2 and TLS 1.3.
* TLS 1.0 Cipher Suites:
Attempted to connect using 80 cipher suites.
The server accepted the following 6 cipher suites:
TLS_RSA_WITH_AES_256_CBC_SHA 256
TLS_RSA_WITH_AES_128_CBC_SHA 128
TLS_RSA_WITH_3DES_EDE_CBC_SHA 168
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 256 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 128 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 168 ECDH: prime256v1 (256 bits)
The group of cipher suites supported by the server has the following properties:
Forward Secrecy OK - Supported
Legacy RC4 Algorithm OK - Not Supported
* TLS 1.1 Cipher Suites:
Attempted to connect using 80 cipher suites.
The server accepted the following 6 cipher suites:
TLS_RSA_WITH_AES_256_CBC_SHA 256
TLS_RSA_WITH_AES_128_CBC_SHA 128
TLS_RSA_WITH_3DES_EDE_CBC_SHA 168
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 256 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 128 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 168 ECDH: prime256v1 (256 bits)
The group of cipher suites supported by the server has the following properties:
Forward Secrecy OK - Supported
Legacy RC4 Algorithm OK - Not Supported
* TLS 1.2 Cipher Suites:
Attempted to connect using 156 cipher suites.
The server accepted the following 11 cipher suites:
TLS_RSA_WITH_AES_256_GCM_SHA384 256
TLS_RSA_WITH_AES_256_CBC_SHA 256
TLS_RSA_WITH_AES_128_GCM_SHA256 128
TLS_RSA_WITH_AES_128_CBC_SHA 128
TLS_RSA_WITH_3DES_EDE_CBC_SHA 168
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 256 ECDH: X25519 (253 bits)
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 256 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 256 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 128 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 128 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 168 ECDH: prime256v1 (256 bits)
The group of cipher suites supported by the server has the following properties:
Forward Secrecy OK - Supported
Legacy RC4 Algorithm OK - Not Supported
* TLS 1.3 Cipher Suites:
Attempted to connect using 5 cipher suites.
The server accepted the following 3 cipher suites:
TLS_CHACHA20_POLY1305_SHA256 256 ECDH: X25519 (253 bits)
TLS_AES_256_GCM_SHA384 256 ECDH: X25519 (253 bits)
TLS_AES_128_GCM_SHA256 128 ECDH: X25519 (253 bits)
In Dex 2.36.0, TLS 1.0 and TLS 1.1 are disabled as expected.
* TLS 1.0 Cipher Suites:
Attempted to connect using 80 cipher suites; the server rejected all cipher suites.
* TLS 1.1 Cipher Suites:
Attempted to connect using 80 cipher suites; the server rejected all cipher suites.
* TLS 1.2 Cipher Suites:
Attempted to connect using 156 cipher suites.
The server accepted the following 5 cipher suites:
TLS_RSA_WITH_AES_256_GCM_SHA384 256
TLS_RSA_WITH_AES_128_GCM_SHA256 128
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 256 ECDH: X25519 (253 bits)
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 256 ECDH: prime256v1 (256 bits)
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 128 ECDH: prime256v1 (256 bits)
The group of cipher suites supported by the server has the following properties:
Forward Secrecy OK - Supported
Legacy RC4 Algorithm OK - Not Supported
* TLS 1.3 Cipher Suites:
Attempted to connect using 5 cipher suites.
The server accepted the following 3 cipher suites:
TLS_CHACHA20_POLY1305_SHA256 256 ECDH: X25519 (253 bits)
TLS_AES_256_GCM_SHA384 256 ECDH: X25519 (253 bits)
TLS 1.0 and TLS 1.1 connections can be decrypted by the attacker, and hence decrypt the traffic to Dex.
github.com/dexidp/dex
github.com/dexidp/dex/blob/70d7a2c7c1bb2646b1a540e49616cbc39622fb83/cmd/dex/serve.go#L425
github.com/dexidp/dex/commit/5bbdb4420254ba73b9c4df4775fe7bdacf233b17
github.com/dexidp/dex/issues/2848
github.com/dexidp/dex/pull/2964
github.com/dexidp/dex/security/advisories/GHSA-gr79-9v6v-gc9r
nvd.nist.gov/vuln/detail/CVE-2024-23656
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
25.8%