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CephApplication · Redhat

CVE-2020-25660

HIGH · 8.8 CVSS v3.1 Published 2020-11-23
Fix available
A fix is available. Upgrade to 14.2.14 / 15.2.6 or later.
See remediation →
93/100
Remediation priority · Urgent
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A flaw was found in the Cephx authentication protocol in versions before 15.2.6 and before 14.2.14, where it does not verify Ceph clients correctly and is then vulnerable to replay attacks in Nautilus. This flaw allows an attacker with access to the Ceph cluster network to authenticate with the Ceph service via a packet sniffer and perform actions allowed by the Ceph service. This issue is a reintroduction of CVE-2018-1128, affecting the msgr2 protocol. The msgr 2 protocol is used for all communication except older clients that do not support the msgr2 protocol. The msgr1 protocol is not affected. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Cephx authentication in Ceph versions before 15.2.6 and 14.2.14 fails to properly verify clients in the msgr2 protocol, allowing replay attacks where an attacker with network access can capture authentication packets and reuse them to impersonate legitimate clients and perform authorized storage operations.

MitigationUpgrade Ceph to version 15.2.6 or later (or 14.2.14 or later for the Hammer LTS) to obtain the patched Cephx implementation that properly validates client nonces and session tokens to prevent replay attacks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CephApplication
Affected:< 14.2.14>= 15.0.0, < 15.2.6
Ceph StorageApplication
Affected:= 2.0= 4.0
Openshift Container PlatformApplication
Affected:= 4.0
FedoraOperating system
Affected:= 33

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Ceph version
    Run 'ceph --version' or check the package version via 'rpm -q ceph' or 'dpkg -l ceph'
    Affected if Version is below 14.2.14, or is 15.0.0 through 15.2.5
  2. Verify msgr2 protocol is enabled
    Check ceph.conf for 'ms_bind_msgr2 = true' or inspect running configuration via 'ceph config dump | grep msgr2'. Also verify port 3300 is listening via 'ss -tlnp | grep 3300' or 'netstat -tlnp | grep 3300'
    Affected if msgr2 (v2 protocol) is enabled and accepting connections on port 3300
  3. Confirm Cephx authentication is in use
    Check ceph.conf for 'auth_cluster_required = cephx' (default) or run 'ceph auth ls' to list authenticated keyring entries
    Affected if Cephx authentication is enabled (the default setting)
  4. Assess network exposure of msgr2 port
    Review firewall rules and network ACLs to determine if the msgr2 port 3300 is exposed to untrusted networks. Use 'iptables -L -n' or check cloud security groups
    Affected if Port 3300 is accessible from network segments without sufficient access controls

Your environment is affected if you run a vulnerable Ceph version (below 14.2.14 or 15.0.0-15.2.5) with msgr2 protocol enabled and Cephx authentication, and the msgr2 port is network-accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 14.2.14 / 15.2.6 or later
Fixed in 14.2.1415.2.6
Interim mitigation

Upgrade Ceph to version 15.2.6 or later (or 14.2.14 or later for the Hammer LTS) to obtain the patched Cephx implementation that properly validates client nonces and session tokens to prevent replay attacks.

Fix this in Ceph Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
27.0 hours of engineering $4,800
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-25660 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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