CVE-2021-23192Network attack vector

Unauthenticated request manipulation via unchecked DCE/RPC fragments

Published Mar 2, 2022 · Updated Aug 3, 2024

DCE/RPC fragment injection in Samba 4.10.0 through 4.15.1 allows remote attackers to alter server requests over untrusted transports. Fragment-protection checks cover the header policy controls but are not repeated across later fragments, allowing replacement data to bypass DCE/RPC signing. The unauthenticated path requires a large fragmented request over direct TCP/IP or anonymous SMB and permits altered server behavior.

CVSS severity4.8
Medium
EPSS probability1.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DCE/RPC fragment injection in Samba 4.10.0 through 4.15.1 allows remote attackers to alter server requests over untrusted transports. Fragment-protection checks cover the header policy controls but are not repeated across later fragments, allowing replacement data to bypass DCE/RPC signing. The unauthenticated path requires a large fragmented request over direct TCP/IP or anonymous SMB and permits altered server behavior.

The record

CVE
CVE-2021-23192
Published
Mar 2, 2022
Updated
Aug 3, 2024
Vendor
PPP Project
Product
Samba
Classifications
CWE-20, T1565.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 2, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=Affects samba v4.10.0 to 4.15.1, Fixed in samba v4.15.2, v4.14.10 and v4.13.14.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PPP Project · Sambaversion=Affects samba v4.10.0 to 4.15.1, Fixed in samba v4.15.2, v4.14.10 and v4.13.14.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
4.8Samba TeamCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.002Transmitted Data Manipulation

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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