CVE-2025-30156
HighCVSS 8.9Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
Ceph versions prior to 20.2.4 and 19.2.6 use the CephX authentication protocol with AES-128-CBC in an unauthenticated mode, using a hard-coded initialization vector and no message authentication. An attacker with a low-privilege key can forge tickets and gain cluster-wide access, including to privileged components such as Manager, MDS, and OSD.
Risk Assessment
The vulnerability allows privilege escalation and full cluster takeover, potentially leading to compromise of confidentiality and integrity of data stored in the system.
Recommendation
Immediately upgrade Ceph to version 20.2.4 or 19.2.6, which contain the fix for this vulnerability.
Original NVD description (English source)
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.