CVE-2021-36780

Unauthorized replica data access via unauthenticated TCP connections

Published Dec 17, 2021 · Updated Sep 16, 2024

Missing authentication in SUSE Longhorn 1.1.2 and earlier and 1.2.0 through 1.2.2 allows remote attackers to read and write replica data. A longhorn-engine replica process in an instance-manager replica pod accepts multiple TCP connections and performs data-plane reads and writes without authenticating the connecting workload. Exploitation requires a malicious pod with network reachability to the replica process inside the Kubernetes cluster; it exposes or alters that replica's stored volume data.

CVSS severity8.1
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in SUSE Longhorn 1.1.2 and earlier and 1.2.0 through 1.2.2 allows remote attackers to read and write replica data. A longhorn-engine replica process in an instance-manager replica pod accepts multiple TCP connections and performs data-plane reads and writes without authenticating the connecting workload. Exploitation requires a malicious pod with network reachability to the replica process inside the Kubernetes cluster; it exposes or alters that replica's stored volume data.

The record

CVE
CVE-2021-36780
Published
Dec 17, 2021
Updated
Sep 16, 2024
Vendor
SUSE
Product
Longhorn
Classifications
CWE-306, T1210
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=longhorn <1.1.3
  2. Affected versionversion=longhorn <1.2.3v

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

SUSE · Longhornversion=longhorn <1.1.3; version=longhorn <1.2.3v

Published CVSS scores

4.8NVDAV:A/AC:L/Au:N/C:P/I:P/A:N
8.1SUSECVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
8.8Longhorn GitHub Security AdvisoryCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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