Description

In the Linux kernel, the following vulnerability has been resolved:

KEYS: trusted: dcp: fix leak of blob encryption key

Trusted keys unseal the key blob on load, but keep the sealed payload in
the blob field so that every subsequent read (export) will simply
convert this field to hex and send it to userspace.

With DCP-based trusted keys, we decrypt the blob encryption key (BEK)
in the Kernel due hardware limitations and then decrypt the blob payload.
BEK decryption is done in-place which means that the trusted key blob
field is modified and it consequently holds the BEK in plain text.
Every subsequent read of that key thus send the plain text BEK instead
of the encrypted BEK to userspace.

This issue only occurs when importing a trusted DCP-based key and
then exporting it again. This should rarely happen as the common use cases
are to either create a new trusted key and export it, or import a key
blob and then just use it without exporting it again.

Fix this by performing BEK decryption and encryption in a dedicated
buffer. Further always wipe the plain text BEK buffer to prevent leaking
the key via uninitialized memory.

Classification

CVE ID: CVE-2024-45004

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.01% (probability of being exploited)

EPSS Percentile: 1.56% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-45004
https://git.kernel.org/stable/c/9e3b266afcfe4294e84496f50f006f029d3100db
https://git.kernel.org/stable/c/0e28bf61a5f9ab30be3f3b4eafb8d097e39446bb

Timeline