Contrast before 1.12.1 Insecure LUKS2 Persistent Storage

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Contrast is a Kubernetes runtime for confidential containers. In versions before 1.12.1, the secure persistent volume feature is vulnerable to a malicious host supplying a crafted LUKS2 volume to a pod VM. LUKS2 volume metadata is not authenticated and, with cryptsetup versions prior to 2.8.1, a header specifying the null keyslot encryption algorithm (cipher_null-ecb) is accepted without error. Because the Contrast Initializer assumes a device is protected if `cryptsetup open` succeeds with the secret seed, the guest will open the attacker-supplied volume and write secret data in plaintext, or under a volume key known to the attacker, allowing the host to read confidential data that should have been encrypted. Contrast v1.12.1 ships cryptsetup 2.8.1, which disables null ciphers in keyslots when the passphrase is non-empty; v1.13.0 adds detached-header validation in guest memory and integrity protection for secure persistent storage. Contrast persistent volumes were not integrity protected, so integrity impact is not considered.

Source published

27 Sep 2026 01:28:25 UTC

Source modified

8 Oct 2026 15:21:36 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 6.9 CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1 · 5.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Contrast is a Kubernetes runtime for confidential containers. In versions before 1.12.1, the secure persistent volume feature is vulnerable to a malicious host supplying a crafted LUKS2 volume to a pod VM. LUKS2 volume metadata is not authenticated and, with cryptsetup versions prior to 2.8.1, a header specifying the null keyslot encryption algorithm (cipher_null-ecb) is accepted without error. Because the Contrast Initializer assumes a device is protected if `cryptsetup open` succeeds with the secret seed, the guest will open the attacker-supplied volume and write secret data in plaintext, or under a volume key known to the attacker, allowing the host to read confidential data that should have been encrypted. Contrast v1.12.1 ships cryptsetup 2.8.1, which disables null ciphers in keyslots when the passphrase is non-empty; v1.13.0 adds detached-header validation in guest memory and integrity protection for secure persistent storage. Contrast persistent volumes were not integrity protected, so integrity impact is not considered.

Source published

Sep 27, 2026, 1:28:25 AM (timezone not stated)

Source modified

Oct 8, 2026, 3:21:36 PM (timezone not stated)

Observed here

9 Nov 2026 04:13:28 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 6.9 CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Contrast is a Kubernetes runtime for confidential containers. In versions before 1.12.1, the secure persistent volume feature is vulnerable to a malicious host supplying a crafted LUKS2 volume to a pod VM. LUKS2 volume metadata is not authenticated and, with cryptsetup versions prior to 2.8.1, a header specifying the null keyslot encryption algorithm (cipher_null-ecb) is accepted without error. Because the Contrast Initializer assumes a device is protected if `cryptsetup open` succeeds with the secret seed, the guest will open the attacker-supplied volume and write secret data in plaintext, or under a volume key known to the attacker, allowing the host to read confidential data that should have been encrypted. Contrast v1.12.1 ships cryptsetup 2.8.1, which disables null ciphers in keyslots when the passphrase is non-empty; v1.13.0 adds detached-header validation in guest memory and integrity protection for secure persistent storage. Contrast persistent volumes were not integrity protected, so integrity impact is not considered.

Source published

27 Sep 2026 02:17:11 UTC

Source modified

14 Oct 2026 13:10:00 UTC

Observed here

25 Oct 2026 04:17:18 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 6.9 CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Secondary · 5.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

### Summary A malicious host may provide a crafted LUKS2 volume to a Contrast pod VM that uses the [secure persistent volume](https://docs.edgeless.systems/contrast/howto/encrypted-storage) feature. The guest will open the volume and write secret data using a volume key known to the attacker. LUKS2 volume metadata is (a) not authenticated and (b) supports null key-encryption algorithms, allowing an attacker to create a volume such that the volume: - Opens (cryptsetup open) without error using any passphrase or token - Records all writes in plaintext (or ciphertext with an attacker-known key) ### Details Contrast uses cryptsetup to setup secure persistent volumes, using the secret seed as key for the cryptsetup encryption. To do so the Contrast Initializer will invoke the `cryptsetup` CLI. If the device provided by Kubernetes is a identified as cryptsetup device, the Initializer assumes a pod restart happened and the device was previously encrypted with the secret seed. The Initializer will try to open the device, and assume it is protected if the operation succeeds. However, due to the unsafe handling of null keyslot algorithms in the cryptsetup 2.8.1, it is possible that the opened volume is not encrypted at all. Cryptsetup prior to version 2.8.1 does not report an error when processing LUKS2-formatted disks that use the `cipher_null-ecb` algorithm in the keyslot `encryption` field. ### Impact Using a maliciously crafted cryptsetup device, an attacker can read confidential data that was written to the persistent volume that should have been protected by encryption. Notice that Contrast's persistent volumes weren't integrity protected, so the integrity impact of this attack isn't considered. ### Patches A partial fix landed in [cryptsetup version 2.8.1](https://gitlab.com/cryptsetup/cryptsetup/-/blob/main/docs/v2.8.1-ReleaseNotes#L14), disabling null ciphers in keyslots when the user passphrase is nonempty. Contrast shipped this cryptsetup version shortly after it has been released upstream, in [Contrast version v1.12.1](https://github.com/edgelesssys/contrast/releases/tag/v1.12.1). However, LUKS header parsing and interpretation remains a large attack surface. Attackers may still be able to modify LUKS headers in other ways, such as triggering automatic reencryption or downgrading to weak ciphers. As a long term hardening solution, LUKS disks is encrypted in detached header mode. The detached header resides in a tmpfs file inside guest RAM, and is checked before it is used to open the device. This has been implemented in [#1731](https://github.com/edgelesssys/contrast/pull/1731) and released as part of [Contrast v1.13.0](https://github.com/edgelesssys/contrast/releases/tag/v1.13.0). In addition, we added integrity protection for secure persistent storage as a new feature in [#1734](https://github.com/edgelesssys/contrast/pull/1734), which was also shipped as part of [v1.13.0](https://github.com/edgelesssys/contrast/releases/tag/v1.13.0).

Source published

28 Oct 2025 17:49:59 UTC

Source modified

27 Sep 2026 11:55:58 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Publisher rating · MODERATE

Contrast has insecure LUKS2 persistent storage partitions may be opened and used in github.com/edgelesssys/contrast

Source published

5 Nov 2025 18:41:15 UTC

Source modified

27 Sep 2026 11:55:58 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.