CVE-2025-30156: Weak Crypto (CVSS 8.9)

Description

Ceph is an open-source distributed storage platform providing object, block, and file storage. In versions prior to 20.2.4 and 19.2.6, the CephX authentication protocol encrypts tickets with AES-128-CBC in an unauthenticated mode that uses a hard-coded initialization vector and no message authentication, allowing an attacker to forge credentials and gain cluster-wide access. Because the ciphertext is malleable and the monitor will encrypt attacker-chosen entity names, an attacker holding one low-privilege key and able to observe CephX traffic can use the monitor as an encryption oracle and splice ciphertext blocks into valid tickets for privileged entities such as Manager, MDS, and OSD. The same lack of authentication also lets an attacker with CephX permissions escalate privileges by flipping a single bit in a service ticket to set its allow_all field to true. This issue is fixed in versions 20.2.4 and 19.2.6.

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CVSS v3.1 Score

8.9

HIGH

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

EPSS — Exploit Prediction

0.0009

Probability of exploitation

0.01%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-327 CWE-327

References

Other References

https://github.com/ceph/ceph/commit/2ba086255de09c8b95177717cc7e9dd4377e2f0f https://github.com/ceph/ceph/commit/3078188a7bdd89e2975280f2a906c71c2f6effd6 https://github.com/ceph/ceph/security/advisories/GHSA-7q3q-3975-qw3q

Frequently Asked Questions

What is CVE-2025-30156? +

Ceph is an open-source distributed storage platform providing object, block, and file storage. In versions prior to 20.2.4 and 19.2.6, the CephX authentication protocol encrypts tickets with AES-128-CBC in an unauthenticated mode that uses a hard-coded initialization vector and no message authentication, allowing an attacker to forge credentials and gain cluster-wide access. Because the ciphertext is malleable and the monitor will encrypt attacker-chosen entity names, an attacker holding one low-privilege key and able to observe CephX traffic can use the monitor as an encryption oracle and splice ciphertext blocks into valid tickets for privileged entities such as Manager, MDS, and OSD. The same lack of authentication also lets an attacker with CephX permissions escalate privileges by flipping a single bit in a service ticket to set its allow_all field to true. This issue is fixed in versions 20.2.4 and 19.2.6. It has a CVSS v3.1 base score of 8.9 (HIGH).

How severe is CVE-2025-30156? +

CVE-2025-30156 has a CVSS v3.1 score of 8.9 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0009, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2025-30156? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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