Crux Agent silently fails SKA preshared key rotation when SHA-512 peering is negotiated
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Sirius Computer, Inc. | Crux Agent | unaffected |
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| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Sirius Computer | Crux Agent |
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Vendor Solution
Upgrade to Crux Agent 2.0.3 or later, which truncates the SKA key to the 32 bytes WireGuard requires. As a workaround, remove any custom settings for "Hash Function" in the agent's configuration (so as to use the default SHA-256 hash function).
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.138% probability within 30 days)
| Link | Providers |
|---|---|
| https://sirius.computer/security-disclosure-policy/ |
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| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Sirius Computer
Sirius Computer crux Agent |
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| Vendors & Products |
Sirius Computer
Sirius Computer crux Agent |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| Description | Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted. For a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the "Enforce SKA Use" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer's traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel. | |
| Title | Crux Agent silently fails SKA preshared key rotation when SHA-512 peering is negotiated | |
| Weaknesses | CWE-252 CWE-325 CWE-394 |
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| References |
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| Metrics |
cvssV4_0
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